Hi,
I wrote a program that allows to communicate with a NXT brick under Linux using a Bluetooth link. With this program you can upload and download programs run them and other stuff. You can find more info and get the source at . Our site is not ready yet (really) but this page should be working.
You'll find also info on how to make Bluetooth working on Fedora Core 4 if you have problems, or at least on how I was able to make it work.
The program is called NXTRC (NXT Remote Command) and is a slightly modified and improved version (v 1.1) of another program of mine called NXT that was available on the NET in the last month or so.
Ciao, GiP