Thought I'd throw an update on here for anyone who's happening upon this dead thread. The mini kegs were kind of neat for a while, but what happened is I had a hefewiezen that didn't completely ferment in 2 weeks, and I put it right in the kegs. Well, 2 weeks later 1 of the kegs had expanded to the point of being unusable and 1 had blown off the bung in the top and ruined the keg (which is what got me investigating).
Honestly, for the 100ish dollars I spent on this setup you could easily build a soda keg dispensing unit.
I went for a brand new GE fridge, a two tap tower, new regs and bottle and I think I only ended up with about 400 into it. However you can find used fridges for $0-$25 in the local paper or free classifieds pretty frequently. Kegs I learned vary quite a bit depending on where you get them from I found a guy in the city that sells them for nearly half of what I got the first 2 for and in my town at least it's much more cost effective to exchange CO2 bottles at the Coke distribution center (though you do have to make a deposit on the first one).
Overall, I think I could have built a decent single keg and picnic tap setup for right around 150 or 200. Been using my setup for about 8 months now, and I can't believe I never did it before. I'm producing clearer, cleaner beer than ever before. With pretty predictable carbonation levels and having a tap in your home is just about enough to make any man happy with life...