The SynCE project has done this. The documentation is pretty good, but as usual I managed to make it hard for myself. Here's what I did:
- Make sure the X30 is not plugged in to the computer
- sudo apt-get install synce-hal librra0-tools librapi2-tools
- Plug in the device
Note that I was already running kernel 2.6.24-19, so I didn't have to rebuild the modules as described in the documentation. If your Ubuntu 8.04 is up-to-date, you'll be running at least this kernel.
My problem: All the installation instructions warn you to blacklist the ipaq module if you have connection problems. So I went ahead and blacklisted it before I even started. Then I fumbled around for a few hours trying to connect unsuccessfully and searching for information.
The X30 only supports Windows Mobile 2003 Second Edition. I don't know all the technical details, but I know it means it used a somewhat different protocol for connecting. In my search for answers, I found enough examples of people successfully connecting to X30s that I kept going. I also found enough references to the "old protocol" or "serial protocol" that I finally realized I should try allowing the ipaq module. I removed the blacklist and, presto, it worked.