Taken the plunge and bought one of these. I've also got the Garmin powered vehicle mount and planning on getting hold of a pole mount to fit to the back of the bike ... Something along the lines of the CU2RACK mount
Check out the sort of thing you can do with it here and don't forget to look behind him as well!:
Check out the sort of thing you can do with it here and don't forget to look behind him as well!: