When you're done with Sync, open Preferences, go to Sync, and choose "Deactivate This Device". That'll disable Sync on that machine.

Note that it won't clear data out of the profile itself, so your passwords, bookmarks, etc. will still be on the local machine. You'll need to delete the profile, or remove whatever items were synced, after deactivating the device.

I strongly suggest you consider using something like Firefox Portable:

http://portableapps.com/apps/internet/firefox_portable

on a USB key, rather than syncing your data to a public machine.

OK...thanx...I eventually did figure that out; its just that on the recently scrapped version of firefox you didn't have to go thru those extra steps - everything was on the drop-down tool menu.

monroe