1. Organize periodic sing-along sessions at your local nursing home. Print out lyric sheets of popular songs from their era and have the kids sing and enjoy the residents to sing with you. Afterwards, if the kids are comfortable with it, have them go around saying hello to the residents. Or schedule a game night and take several games - assuming the group is okay with that. Simply call your local nursing home and ask to speak to the Activities Director. Many also have one birthday party a month - and often they welcome people to help with that.
2. Make cards for people - kids in the hospital, veterans, misc people in the nursing home (who don't get much mail).
3. Adopt a park or street for trash pickup