This is far from an elegant solution, and I'm SURE there's a better one. That said, this is what I do. I connect the two computers via AEBS (I mount my desktop on my laptop). Then I drag the user file (I'm pretty sure that's the right one) from the desktop to the laptop, obviously replacing the laptop one.
As I said, far from elegant, but it works. It mostly works because I really don't use Palm much on my laptop. In fact, I went months before updating the laptop files.
I'll be interested to read others' solutions.