I have been trying to figure out why I can’t go buy a TV for a monitor. They’re cheaper than the dell 2405FPW, even the flat-panel ones. For the price of one of those dell monitors, I could go get 2 20 inch TV’s for the price of one of these, and have the most awesome computing experience ever.
Is there something hardware-wise that would limit me from doing this?
The resolution on TVs is extremely poor. It’s pretty much impossible to read text unless you’re willing to drop your resolution 640 x 480 or spend a lot of money on a HDTV and a video card with HDTV-compatible output.
^^^ What he said.
All you need is a video card that supports TV-out; many, many video cards do. From there you just need a composite or S-video cable to connect the output from your video card to the TV.
However, it will look awful. The average dot pitch on a CRT monitor is .22 while it can be as much as .55 on a CRT TV. This means that the pixels are (usually) more than twice as far apart on a TV as they are on a dedicated computer monitor. Also, there are far fewer pixels on most TVs than CRTs, so don’t expect to run anything higher than 800x600 (mostly likely you’l be stuck at 640x480). Bleh!
Of course, it’s all different when it comes to LCDs. But honestly CRT monitors are CHEAP these days. I got my current monitor (a 19" SGI (which is Sony under the hood) for $159 with shipping. I’m sure that BestBuy or CompUSA would have EVEN BETTER deals these days.
[ASIDE] … when I was poor and couldn’t afford to buy a television set, I hooked up my video player to my Amiga 1200 monitor… best damm picture I ever had, and a reliable TV for five years before it finally gave up the ghost… 
[/ASIDE]
Note that you can hook up a HDTV to a computer, and it will look fine - in fact, most HDTV’s have DVI ports (which any decent video card also has) or an HDMI port, which can be attached to a computer’s DVI port with a simple adapter.
Computer monitors contain lots of extra control electronics that TVs don’t. Better resolution aside, you don’t want your straight lines to be wavy, your colours to bleed etc. Overcoming the limitations of a cathode ray tube is difficult and expensive, which is why TVs are cheaper than monitors.
At a pinch you could do it with a TV, but you’d give yourself a kicking headache if you had to look at it for too long.
Once they buy a HDTV it defeats the reason the OP asked about a TV.
I’m sorry, I meant to add the disclaimer that I was planning on upgrading with LCD TVs. Does that make any difference?
Not unless it’s HDTV, no.
Yes, that does make a difference - while conventional CRT TV’s make poor monitors, many LCD TVs are suitable for use as monitors. Beware, however, that many of the smaller LCD TVs are rather low resolution - 640x480 seems to be common on the 20" LCD TVs, from a quick check at Best Buy’s webpage, and lack the DVI or HDMI port you would want to connect to a computer. In comparison, I know that the Dell 20" LCD monitors have a resolution of 1600x1200.
The larger LCD TV’s have HDMI ports, making plugging them into a computer as easy as finding a DVI-HDMI convertor. However, again checking Best Buy’s site, most the 23" and up LCD TV’s have a resolution of 1366 x 768, which is quite a bit less than the 1920x1200 you get on a Dell 2405FPW.
Even a really expensive HDTV, that will do 1080p, is still only about as good as a computer monitor, resolution wise (albeit much bigger). ISTR that 1080p is 1280x1024, which most monitors can do comfortably.
I’ve got my media center pc hooked up to just a standard 27" boob-tube. Let’s just say: my emulated NES games look great!
Here is how to hook up a DVD player/VCR/VG system to a computer monitor. For sound, simppkly run the audio out to a stereo.