I've talked to quite a few people, all of which wanted HD, HD is a big thing and has almost turned into a buzzword(or has).

So what is HD?

HD is any screen that has a resolution of 1280 by 720 or higher regardless of whether its "I" or "P" HD is not the size of the screen. HD is not the aspect ratio, it can be HD whether it is in letterbox(4 by 3) like a standard TV or whether it is wide screen(16 by 9), however if the aspect ratio is modified the picture loses quality as you see in the rogers HD commercial viewable here

HD is like comparing an average public school students drawing of a picture using big crayons compared to a decent university graphic design students drawing of the same thing(a little bit exaggerated but hopefully you get the point). HD is about quality, not about size.

So what is the difference between "I" and "P"

I updates even coloum pixels and than odd coloum pixels and switches. Because of this "I" for some people comes up as flicker and makes it hard to watch I find that this only happens when I'm very tired) on the other hand updates the screen in a row at the same speed, getting rid of eye strain, this is basically only important if your using your TV for long periods of time or you notice that your eyes hurt after using it on I.

Are DVDs HD(aka SD-DVD)?

No DVDs are not HD Using a progressive scan DVD player you can play DVD's at 420P(instead of the regular 420i) which makes it easier on the eyes. If you have a HD TV, you may want to consider getting a upscaling DVD player because it will convert to the format your TV supports (instead of the TV having to do the conventions) and may save some lag that you get when playing a lower quality disc on a higher quality TV.  This will not make your DVD higher quality as you are limited by the lowest common factor.(Upscaling makes your TV think it is a higher quality picture and may make your picture look better because it is run in the TV's native mode, however this is not higher quality(than 420P), it just means your now seeing it as 420P instead of a lower amount that you had before hand.), some people say that an upscaling dvd player produces a higher quality picture by compairing it to the next, this is true to a point, however I find it odd that regualar DVDs do not already have this property as it has been around on computers for a long time.

What do you need to play HD?

You need HD content

Blu-Rays are made for 1080P. However you do not need a Blu-Ray player to view Blu-Ray movies, you can download them and play them on your computer. There are currently no providers to my knowledge that actually broadcast there signal is 1080P because of the expense to do so. The highest is 1080I and 720P, so if your going to be using your Television to watch television than you can stick with the 720P/1080I television. HD-DVDs also broadcast in HD but they lost the content war like Beta max vs the VHS.

You need the right cables
High definition cables include the following

HDMI(The Best)
DVI(Very good)
Component Cables(very good)
VGA(some are not capable depending on rating and are analog so can cause eye strain)(good)
S-Video(not for 1080i or 1080P)(average)

you must make sure that the cables match both the TV and the player, you can get ones that go from one type to the other if needed.

Do you really need 1080P?
If you answer yes to any of the following questions you may want to spend the money and invest in 1080P

You use your TV for a computer screen
You play or plan to play XBOX 360 or PS3 on your television
You have a television greater than 47 inches and you plan to sit closer than 6 feet.
You plan to use your television to view high quality pictures.

Can you put HD on a DVD?
The answer is yes, however a  standard dvd player(you may be able to find machines that can play higher video amounts) will not be able to play it. you will be able to run it on  a computer. I doubt that it would play on a blu-ray or HD DVD player, however I don't really know You could also technically put HD onto a CD but you would get a very limited amount of time.

Can you really get HD content in small files? Yes you can you can get DVD quality movies 2 hours or longer in files 1/4 the size. The same applies to HD content(I'm not 100% sure about the ratio of HD), however doing this will make it unplayable on many machines as DVDs and HD-DVD/Blu-rays as they have all sorts of formating and security that make the discs playable on different machines. Some machines may tolerate the different formating, other may not, either way you can play them from your computer to your TV if your computer has the right codecs I personally recomend http://www.mediacodec.org/

Mega pixels
When buying a camera, what you plan to use it for should influence what you buy. If you plan to show it one a standard definition TV via cables, you only need a 0.3MP. If you plan to show it on a 720 pixel TV(either I or P) you need close to a 0.9 Mega pixel camera. If you want it on a full HD(1080 px) you only need a 1.7MP camera. If you plan to use it on an expensive LCD monitor you need not buy more than a 4 MP camera. If you have a ungodly amazing screen(the biggest shown on http://en.wikipedia.org/wiki/File:Aspect_Ratios_and_Resolutions.svg at 2560 by 1920) you still only need a 5MP camera. You technically can see part of a picture on the screen and pan but I'm considering if you want to see the picture full screen without panning.

In summary
Standard TV/DVD 0.3MP
Facebook max size: 0.5MP
720px TV 0.9MP
1080 TV 1.7 MP
LCD monitor 4MP
Amazing monitor 5MP

Do you really need HD?
Many people think that they have HD when they don't, some people have HD and think they have standard definition. Only people who become "experts" can actually tell whether your getting HD or Full HD or not without compairing them to other machines. If it looks good to you, don't worry too much about upgrading, save your money.

What to look for in a digital camera(listed by what I think is important)

Name Brand: Generics or lesser names can be good, but with a name brand your more likely to get a higher quality camera. Cannon is #1, so if you can afford there prices go for it, as the better make brands will produce supior quality pictures in general, athough some brands you may pay for the advertisements and the "feeling" or prestige produced by owning one(for example people get this feeling from owning an Ipod, even if they could get the same product from Sansa for a lower price or get a supior product for the same price, however Sansa is a fast follower, not a leader so it will have products come out after the latest and greatest comes out from Apple)

ISO: Sensitivity, this is how much information from light the camera can take in, however as with cheap stereo systems, when you turn up the volume or sensitivity in the cameras case, you also increase unwanted data(different colors). The software/firmware on a better camera will better handle this and fix there problems without later edits on a computer, you will need advanced software and quite a lot of processing power to do these edits on your computer(this in the future may not be an issue).

Battery: A generic long lasting battery is best. A long lasting battery is good even if it is propriatary. Generic batteries are good if you carry extra. A short lasting and propertery battery should be avoided because proprietary almost always means no competition which means higher prices and with low life you will need multiple of them.

Size(of the camera): Smaller is better as it is more portable, but not so small that you can't use it because your hands are too big.

Size(of the screen): A screen you can comfortably see without squinting is best, as too big of a screen will eat batterys and too small of a screen you won't be able to see.(you may say uhh duh, but a lot of people don't think about these kind of things)

Compression(Video/Picture): This is important that your camera has a good(or even bad) compression system. I purchased a 4MP webcam for $10, it has no compression so a clip recorded in 640 by 480 can easily top 4GB for a 5 minute video Compression is less important on still pictures, but you should still have at least basic compression(my FE-300 lets you choose between low and high compression, if I have text to be read I use basic compression, if I don't I use high compression.

Lens: If you plan to do professional photography buy them, but if your using it to take pictures of your kids and not things that require special lens(such as taking pictures of large building without them looking slanted), save your money and buy a non replaceable lens camera.

On board software: Software on the camera can make pictures look better without you having to edit them manually. Face dectection is a neat add on but not nessicary and I don't know how much more advanced it has come but it could not detect my brothers smile. So don't rush out to buy it. If your camera doesn't automatically optimize your pictures you can download one of several programs. I personally use Pisca, Paint.net, gimp

Durability: Every time I go into Wal-Mart I almost buy the 0.3 MP camera. Why because its made for kids, you can drop it and it doesn't break! This is much different from most expensive adult cameras which can break from a very small drop.

Connections:You want some kind of USB connection otherwise you won't be compatible with most computers, you may want to make sure you get USB 2.0 highspeed capable(do not buy full speed!). You don't need the cable as you can buy it seperatly if you know the type of USB connection. You do not need a USB connection if it has a card and you have(or are going to have) a graphic card reader for that particular type of card.

Graphic Card: SD are about the cheapest. So if you can get that, good. Otherwise just make sure you have a reader for that card or a USB connection for your camera.

Optical Zoom: Optical zoom allows you to zoom up without losing quality, digital zoom is nothing special and ussually you do not want to do this until you edit it on a computer or printing station.

Megapixels: You really don't need more than 5MP unless your printing them out. It really depends what your using them for. Just for fun,if you want to put your camera on an IMAX screen you would need a 104.4 MP camera for standard definition IMAX, there is also HD IMAX which is significantly higher resolution If you plan to digital zoom up on people later you may want a higher resolution camera.

Sources
CNET Digital Camera guide
Random Websites Advertising Resolutions of Cameras. Double checked using other sites, you can check the resolutions yourself by multiplying the pixels(say 640 by 480) = 307200 or ~1/3 MP(mega = 1,000,000 pixels)
Peter Downie(memory/usage of cameras)
Camera Book(I may update name of it, if I can find it)
http://www.tristanpipo.com/2005/03/18/last-update-was-sunday