Here is a unique idea:  Cup Holder Car Mount for your Edge!  This looks great and your Pre is right at your fingertips for changing songs, scoping out the internet, answering the phone.

Take a look at the pictures.  I'm sure you will agree that this is a heck of a lot better than putting it on your seat!  The popular Cup Holder Pedestal is about 5" tall.  It features an adjustable flywheel base that expands to fit varying cup holder opening except for those that are so large that the 7-Eleven Big Gulp falls over    

Features a quick release cradle for your Edge.