Depends where you are going, but I always made sure I could fix a flat: Tubes, patches, tire irons, RueGlyde (or soap), compressor and a c-clamp (for breaking the bead). Can save you quite a few hours of waiting...
Other than that, a LeatherMan, the stock tool kit (the old one) and a test lamp is pretty much what you need. Clutch lever, throttle and clutch cable if you're heading out in the boonies. And fuses, assorted bolts, JB Weld, gorilla tape, zip ties, and some steel wire and electric cable of course.
Have a nice trip, wish I could go too.