If you've upgraded to 10.5 like I have, and your system is still OK, but GlowWorm is still in your process list in Activity Monitor, here is exactly what I did:

Open Activity Monitor
Quit the Glow Worm process (called glowwormd or something like that)
Then to uninstall,
Download GlowWorm FW Lite (from this page)
Mount the .dmg GlowWorm-1.5.3b4 (or whatever it is exactly) on your desktop and open it.
Right click (or Control-click on 'Installer')
Show Package Contents
Contents > Resources > Uninstaller
That should uninstall all GlowWorm FW related files without actually installing them first.

Restart to make sure that process isn't still running.
Good luck!