aye, a GPS is awesome for a bike.
can't remember if i've posted this before, but here's my setup as posted in my bike forum:
Finally got myself sorted out with a GPS. After our Euro trip last year we swore we wouldn't do it again without one. The memory of our little faux pas in Geneva that caused us to be lost for about 3 hours in the dark - eventually resorting to hiring a taxi to lead us to our hotel - still haunts me yet...
Anyway! One Tom Tom One (v2) UK & Europe, with full street mapping all over Europe - £200 from Comet. (You can get it even cheaper online from Amazon etc. but I just HAD to buy one that day...

) Plus a nice carry case from ebay for under a tenner:
One handlebar mount from ebay - £18 delivered:
Fitted:
It's not waterproof, so using the following ingredients:
... one ghetto fabulous custom-made rainsuit
All in all I am delighted with this setup. Who needs to spend a fortune on a bike-specific unit? This does it all, I think.
\chuffed
Still need to fit a 12V power outlet to the bike though, cos the battery life on this one is only a shocking 2 hours. I had it in my head it was 8 hours when I bought it. Ah well, I always wanted one anyway.
and an update on the battery life: it's completely dead and always needs to be plugged into the power socket.