It depends on what you want to do with it. If you are thinking helmet or bike mounted video I have no advice. I find that I seldom want video capability on tour and therefore helmet or bike mounted cameras don't appeal to me.

If you are thinking still photography with some video capability... There are a lot of very nice point and shoot cameras these days. If you want a bit more, the Olympus Penn 4:3 models are a good fit for touring. The Nikon Coolpix 7000 is also super nice and fairly light and compact. I would avoid the big DSLRs unless photography is the primary reason for the tour, and even then something like the Olympus or Nikon models I mentioned might suffice.