From TeraGrid Wiki
Alternative Hotel for NSF Open House
Arlington at Ballston
4610 N. Fairfax Blvd
Arlington, VA 22203
This is about 3 blocks from NSF, directly across from the I-66 entrance on Fairfax. They also have free parking.
Weekend rate is $95; weekday is $239 (Your mileage may vary, but it's worth a call)
(from Lfm 20:13, 23 January 2008 (GMT))