First off, I 2nd the recommendation of "Best Friends." I've been to the Utah sanctuary in person, even donated a carload of stuff, leftover from when my dog was alive -- I think, no, I know that she would approve. Anyway, Best Friends carefully screens and follows-up on the animals that they place in "forever homes"; those they can't place stay there as long as needed, even for the rest of the animal's natural life. There may even be a BF affiliate near you: http://network.bestfriends.org/GoLocal/Default.aspx
Secondly, my third cat (shhhh, according to my landlord I only have two) I got from a person I was supposedly doing a favor for by taking. The cat is 5 years younger, bigger, and more aggressive than my other two so at first I sort of regretted having taken him in. But in the five years since I have had him, he's settled down quite a bit and all three manage to co-exist without bloodshed, which I consider a success.
And when I thought about it, the persons whom I got this 3rd cat from are thankfully long gone from my life, but the three cats and my purse (and myself) are the only things in my home that I could not easily replace or live without, so win/win for me. :)
My only problem now is how to be a minimalist with three cats...is it possible? Not to hijack your thread, but I'd appreciate any follow-up leads/links anyone.