Apparently there are adapters that would allow you to mount old Canon lenses on EOS bodies, but they are either cheap and nasty, or expensive and work okay but not great. IMO you're better off getting a used or refurbished DSLR with lens. You can get a factory refurbished Canon XS with lens for $400 direct from Canon...you even get a 90 warranty!
I've been looking around and learning about cameras lately, and my dad has told me that he has some Canon film SLR lenses from the 70's when he was into photography in high school. From what I've read on the internet, those lenses are still compatible with today's Canon digital SLRs, even though you might have to get an adapter and something about a focal length conversion. This leads me to think that I might be able to get a used Cannon body from a few years back for super cheap to use with these lenses and end up with a camera not too far from today's entry level DSLRs. Is there a flaw in this logic?
I did a quick Amazon search and ended up with a list of yesterday's used cameras. It looks like I can get a kind of awesome camera for around $300 or less if I miss out on some modern features like HD video filming and deal with using an archaic memory card. Are the sensors or anything else significantly worse in these older cameras?
Let me know if I'm completely off base. I'm an amateur photographer, so that could very well be the case.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic