Walnut Creek The downtown Walnut Creek area offers shopping, bars, and restaurants.
Clayton One of Concord's next door neighbors, Clayton is a bit more rural than other communities and still offers somewhat of a small-town atmosphere.
Pleasant Hill This neighboring town is primarily a typical family suburb, but it does offer options for food and shopping.
Mt. Diablo State Park (http://www.parks.ca.gov/?page_id=517, (http://www.mdia.org/spinf...) - As one of the tallest mountains in the Bay Area, Mt. Diablo dominates the area landscape and provides an escape from the suburbia which surrounds it.
Berkeley - Eclectic, political and always interesting, Berkeley is only a 20 to 25 minute drive away. Alternatively, using BART, either a) transfer at the MacArthur station and exit at Downtown Berkeley, or b) exit at Rockridge and walk ~2 miles to downtown.
San Francisco - Although "the City" feels a world away, it's just a 45 minute BART ride to the Embarcadero or a 35 minute to 1.5 hour drive, depending on traffic.