I am looking for a device that can do a lot of things-car use,motorbike use (must be able to link to headphone),and outdoor use (OS mapping etc). Does such a thing exist,I would like a unit that the maps and satnav systems can be swapped over on sd cards or the like without having to use a computer link every time,totally waterproof is not too important and for the motorbike I would prefer it in my pocket and rely on voice directions hence the headphone compatability. The people at Currys and Halfords could not really help so I thought I'd ask the experts.