Thanks for the compliments guys...But I am no pro. I still have a hard time with the terms, much less the application of those terms....I've got a few friends with photography degrees, so I really do know just how little I really understand it.
Boudster,
For less than $300 you're unlikely to find a digital camera that you can change lenses on. So you don't really need to pay too much attention to that kind of thing. If you're willing to look at used cameras, you can probably find a few in your price range that are the dSLR-like cameras. You can't really change lenses, but there are a few lenses that you can screw into the front of the existing lense. You don't get nearly as good a quality as you would with true swappable lenses, but you do get some improvement. This is the type of camera I have and there are two lenses that I'd like for it, one is a macro lens and the other is a telephoto. The two together would set me back about $450....That's a good sized piece of cash towards a true dSLR, and I haven't made up my mind which way I want to go yet. There are lots of cheap screw on filters for cameras that help to combat glare, blue-tint, etc... Some people use them to help combat the glare from the glass on the aquariums. I haven't ever used mine, which is something I should probably play with some.
I agree with Kabuto, that the macro setting is important. I generally shoot everything except the full-tank shots in macro mode. Without true macro lenses, (dSLR), you're just not going to get the extreme macro shots you see on reef central. Even putting my camera in the underwater housing and sticking my camera in the tank to get closer I can't match those kinds of shots. Raw format is nice if you're a pro or semi-pro, but for most people it's unnecessary. You have to find software, or plugins for your existing software that will support it, but if you do, then the raw format gives you a bit more power to fix shots in post-production than if you're shooting jpg images.
Anyone looking at buying a camera should totally disregard digital-zoom specs. This is a totally useless feature that's only use appears to be to sell cameras. You can NOT take pictures that come out using the digital zoom function on any camera. This was a feature on my camera that I was excited by when I started playing with it. I spent one evening filling up my cards shooting really close macro shots using the digital zoom. They looked great on the display of the camera. However when I looked at the images on the computer they all were super grainy. I got online and hit one forum after another trying to find out what I did wrong. Across the board everyone said that digital zoom can't be used to get a decent shot.
Photoshop elements is a good piece of software from everything I've read/seen. It's also a fraction of the cost of the regular photoshop. I haven't used it yet. I generally use a combination of several different free-ware image processing programs. I should spend some time in photography forums and see what cheap/free software folks are liking for processing their images.