Useful Services Exchange (U.S.E.), a time-trading barter sstem to exchange services among Reston/Herndon residents, will hold its annual potluck dinner/business meeting on Sat., Jan. 25, from 4:30 to 8 p.m. at the Unitarian-Universalist Church of Reston, 1625 Wiehle Ave., Reston. All current and prospective members are invited. No charge, beverages will be provided. To RSVP or get more information, call 703-435-6283.