Our group volunteers at our local library. The kids wash all the toys, tables, puzzles, chairs out for the kids to use in the children's area. The library LOVES this as it needs to be done for health reasons, but none of them really wants to do it. We moms love it because the kids really do it, not us! They divide the toys into the ones that can go in the sink, the ones that need to just be wiped down, and the ones they need to put in bags for the librarians to send out to a professional cleaner (stuffed animals, etc.). Then they dry everything, and put it back out, pull out the fabric toys that are back from the cleaners, and generally just tidy up the entire children's area. The librarians have been so thankful!
We have also made scrap-quilt blankets for our local shelter and the kids got to drop them off after they made them.
We have decorated paper place mats for the local nursing home, so the residents see cute drawings and notes when they use them.
Hope these ideas help!