Wrote a simple script that uses wxPython to create a system-tray icon which displays whether you are currently recording anything on the local MythTV back-end (playing live TV also counts as recording).

When the /dev/video* devices are in use, the icon shows red, when not, it shows black. Mouse-over shows the number of active recording sessions when active. Double-click closes the application.

Tested only with wxPython 2.6 and Python 2.3, use at your own risk.

You'll likely want to start it in your graphical desktop startup scripts with something like:

python recordingdevices.py &