I just noticed this thread - I've been knitting kitty blankies for my local shelter for the past year+. They LOVE them, and every time I take some in, the staff members are very happy. I do use acrylic - some that is donated to me, leftovers from other projects, or I buy cheap stuff on sale or use my Michaels/Joann coupons. I knit them approx. 24x24", on size 10.5 needles, using a double strand throughout.
Good job for those of you helping!