Volunteers for Manna Food Center are at the Rockville Farmers Market every Saturday, receiving produce purchased at the market for donation to needy families in Rockville and Montgomery County. Buy some for yourself and some for someone else! I noticed yesterday that some of the vendors (Query Mill Hill Farm) also contribute to the collection themselves.
The best part of the farmers market is finding things you don't see at the grocery store. Yesterday there were some tiny tasty cherries (available for probably one more week), Osaka purple mustard greens and bunches of little sweet pink turnips (pictured at right -- 
despite the fact that my attempt at photographic culinary artistry looks more like a pink-eyed alien creature than a delicious dish, they were both really tasty). One vendor said he expects all of the 4 kinds of eggplant grown on his Virginia farm to be ready next weekend. My favorite splurge at the market is a bunch of fragrant pink stargazer lilies, which open slowly over the course of a week or two and give the whole downstairs a lovely aroma, and are sold by the couple from Farmhouse Flowers.
Another note about Manna: In addition to collecting food from the farmers market, Manna Food Center also runs a great program called Smart Snacks, which "provides hungry elementary school students in Montgomery County with 10-15 nutritious and kid-friendly foods for the weekend in backpacks handed to them at their local school." See their website for details on this and other programs at Manna.