I'm a big fan of Pump it Up's drop-in sessions, where you can let the kids run (and jump) free during non-party hours. The San Francisco location is offering a deal for the next two days - get a ticket for 10 drop-in sessions for $35 at the Mendell Street (SF) location. It's good through August 31, 2011 and is half-off the normal price. And better yet - you can use it for one kid ten times, or bring in a group of kids and get use one session for each kid with you (insta-playdate).
Get the Pump it Up deal here, at Mamapedia.