Originally Posted by OMG_WTF
Are you able to get a mini (or micro?) usb cover?
These are used on some Garmin GPS devices, such as the nuvi 500/550.
It looks like this (top right):
Maybe something like a waterproof cable clamp?
There are no rubber covers in production for the mini/micro connectors. They fit so tightly onto the units that I think it would be impossible to fit in there. I always use dielectric grease on my Garmin connections to avoid corrosion.