It's only about a ten minute walk to the SFO int'l terminal if you don't want to take the bus. Admittedly, there's the annoyance of clearing security again, but I wouldn't call it nearly impossible to get over there.

The first time I went into the SFO IFL on a p.s. flight, the attendant had a bit of an attitude ("well, I *guess* we can let you in..." Thanks, lady, I'm pretty sure I paid a healthy premium for the right to enter...), the second time, no problem.