Everything at SFO is walkable. The terminals are basically a full connected loop. There are buses (and soon a train) but its a waste of time/effort unless you are unable to walk very far. Your recommended path will be to make a right turn when leaving the F pier (I assume you are flying AA) and walk through the new int'l terminal lobby, then over to the South (oops now called 1) terminal where the B pier (gates in the 20s) is located. If you have a few extra mins, there are interesting things in the int'l terminal (unsecured area) such as a library/museum which is a full scale replica of the original SFO.

[This message has been edited by Eastbay1K (edited 09-25-2002).]