[Brian]

If you take a look at the "Creating a computer-to-computer network" topic under the Help menu, you should be able to use those steps to connect your MacBook and iPhone directly and sync them, even while traveling.

If that doesn't work for your purposes, you can set up an account with one of the organizations in this thread. You can use the services they provide in the same way you'd use an iDisk to sync when you're on the road, but at less cost.

Do either of those options help?