ray's two cents :
Hmm, working with disabled kids sounds like it might be cool. Pipe cleaner spiders too. 
 I'm not really a chatter, despite what my post count might indicate, so I don't know how much good I'd be to the old folks. I tend to go all quiet when I'm talking to people I don't really know. 
 (Although if they just need a listening ear, that's a whole other story... 
)
I worked in Animal rehabilitation and with the local Indian Education groups as a kid.
You can also volunteer at the hospital or the local animal shelter. There is often a need of people to just visit with the sick who have no family.
There are also other groups like the salvation army, meals on wheels, and hotlines in need of volunteer counselors.
If you are interesting in animal rehab, most ares have a local rescue group, zoo, shelter, or other such things that are in need of people to just come and "socialize" with domestic animals, or help tend to sick or injured animals,c lean cages, groom, feed and so on.
The local rehabbers found out that I had the patience to raise mammals, and started sending me orphaned babies. That was a pain but I did it.
That is a good education for teaching teenagers  about teen pregnancy when you have to get up every hour to feed a hungry baby then find someone to watch it and go to school the next day. And forget trying to get homework done , be apart of after school activities and hang out with friends when you have something young and delicate in need of constant care.