Originally Posted by The Pony Feeder
Why not buy a PDA and run Tom Tom via that! Gotta be the way to go, at least then u can have the use of the PDA for other things aswell!
www.totalpda.co.uk 
Been there, done that...
I found it to be (as with any PC) unreliable, tomtom sometimes randomly crashed or conflicted with other system files, sold it in the end, your best off with a dedicated satnav.