I have not read through all 6 pages of responses, so this post may be a repeat. I also am retired and, alas, trying to live on a very limited Social Security income, so there is not much money available to buy fabrics all the time. Then I discovered
http://www.quiltsforkids.org which sends you quilt kits for you to complete. You supply the batting, assemble and quilt the project and provide the packaging and postage to return the quilt to them. They distribute these quilts to children's hospitals and NICU's all over the country.
This keeps me busy all day, I feel as though I am doing something to help sick children, and it doesn't cost me too much.
The organization does request that you send them one of your own quilts as often as you can to supplement the kits, which is what I try to do at least once a month and I feel as though I am contributing at least a little. I make NICU-size quilts which are only 38" square and don't require a lot of fabric so the expense isn't too bad. I just watch for sales and also use coupons at Joann's.
Hope this helps and that you find a charity that "fits" your situation. There certainly are a lot of wonderful suggestions here.