You can, but here are some things to keep in mind:
DLP replacement lamps aren't usually cheap--varies by model and year.
Personally, I can't stand the RGB color-separation that you can perceive when moving your eyes around a DLP screen.
Check what kind of DVI port that is (DVI-I vs. DVI-D) and verify that your computer/PS3 have that port.
Older TV's will implement overscan--what that results in is only ~95% of the image your computer outputs at a given resolution will be shown at the TV's "native" resolution--amounting to all edges of the screen being cropped out. Newer TV's will allow you to reduce/remove overscanning, but older ones usually don't have that option. Here is a great write-up of the situation: http://mjg59.dreamwidth.org/8705.html
However, assuming the connections work, there's nothing keeping you from using the TV with your computer/PS3, but keep in mind you'll probably have overscan issues (at least with your computer--not sure about your PS3).
Also, if that TV is anything like the one I got rid of recently, it's going to be a good 200-300lbs, so make sure someone else goes with you if you buy the thing.