I think you're absolutely right in wanting to find a new home for your cat - but I'd recommend not using Craigslist. Laboratories use it to pick up cheap or free specimens for experiments. Ask your vet where's the best place to post his availability, and do be sure to ask a reasonable adoption fee so that he doesn't end up in a lab cage (or an Asian kitchen!) Your vet can help you decide on a fee too.

Love, Columbine