I have installed Xubuntu 6.06 on my (and I use the term loosely) Fujitsu P1120. Actually, Iâ€™ve installed it about six times so far.
Xubuntu promises a lighter weight window manager for use on older or slower processors like the 800 MHz Crusoe in the P1120, but installation from a netboot is not at straightforward as installing the Ubuntu desktop. The instructions at https://help.ubuntu.com/community/InstallingXubuntu help a lot.
The good news is that the display is automatically configured with the right 1024Ã—600 resolution. The bad news is that the mouse freezes after a suspend-resume, the wireless doesnâ€™t yet work though the Networking tool says that itâ€™s enabled, and I canâ€™t yet persuade it to use the pre-existing encrypted filesystem that is happily used by multiple JDS installs on the same machine.