Bought a
sat nav for my car yesterday. Today, despite it piddling of rain
I had to try it out on my bike, so ventured out!!
I used the standard screen suction mount thingy and just sucked/mounted it on the rev-counter glass
Here we go; youtube messed with the quality, but if you persevere you will see (and hear) it in action!!
http://www.youtube.com/watch?v=bJ-s5wPj9eU