I came across this cool idea that just started up: GiveCorps. Two Baltimore based women who saw success in the financial industry started an organization that is sort of like Groupon for non-profit causes in Baltimore. They call it "Give and Get" - you pick a cause you'd like to contribute to (that's the "give") and local merchants offer some discount as a reward ("get") if you contribute to that cause.
There's a limited selection of causes on their site today, but one of my favorite restaurants (Woodberry Kitchen) is offering $10 off any meal bill over $25 Sunday through Thursday as one of the "gets." Very cool.