Bevscountrycottage.com has one of the longest lists of sharities (and for charity pattern links) I know of. I do mostly hats and scarves for he homeless and preemie caps lately... with some projects for Kids at Hopkins (see the Ravelry group I'm in fo that one)... some chemo caps thrown in as well.

*Most* groups probably wouldn't care much about the cats *if* you laundered them right before sending them (to be on the safe side, there's always the laundromat and boxing there after drying, to keep new cat dander from hopping a ride).

Pet and people shelters both often have needs and guidelines posted on their websites, too.