Replacing my television with my monitor

In just over a room, I’m moving from my gigantic room to a teeny dorm room, which I’ll be sharing with another person. Quite the change. Space will definately be a problem, so I’m thinking of eliminating my televison to save space. Here’s where you come in:

My idea is to use my computer monitor as my television. Surely, there is an easy way to do this. I need to be able to do the following on my monitor, without having to unplug it:

Watch DVD movies (already have a DVD drive)
Play my PS2/Dreamcast
Watch cable TV

Is there some sort of hardware adapter, or new video card I can get to make this upgrade? I don’t mind buying a new video card, although I’d like it if the card were something better than the Geforce3 Ti500 I have running currently. Any quick solutions for the problem?

You want something like this. I’m sure other manufacturers make similar products.

I used an ATI TV tuner to watch TV on my computer. It’s just a PCI card with a coaxial input on it. The picture quality is decent (the ISA cards had PERFECT picture but the PCI ones seem to be a little worse) and since it’s a coaxial input you can probably hook the video games system up to it. IIRC, these TV cards cost about $70-80 CDN.

What you want is an ATI All-in-Wonder card:
http://www.ati.com/products/multimedia.html