GTK Python Roku Remote
Based off of kmote.py http://code.google.com/p/kmote/
You need GTK and Python 2.7 installed for this to work.
Run with python2
You'll need to edit the desktop file for you.
If you want to build something like this youself you can telnet to port 8080 and enter commands:
press s - select/ok press p - pause/play press u - up press d - down press r - right press l - left press f - FF press b - Rew press h - Home press k - back press i - info press p - replay