hemtrav, if you show up at the Visitor Center in Lone Pine on Friday, especially at 2 PM, you are sure to get a walk-in permit, free. If you check the Unused Whitney Permit info, you can see how easy they are to get in October.

Last year, there were 17 no-shows the first Saturday in October, and they become available at 2 PM on Friday. If you are there at that time, you will get one.