I've connected my comms/nav kit to the spare wires that are meant for the accessory socket on the left hand side of the bike, about four inches forward of your left knee. It's not a switched supply though. It's on fuse 3 as mtcm101 says above. Using crimped blade connectors and then wrapping the connection in self-ammalgamating tape has created a setup that I can remove easily in the future and is weather proof.
I connected my Zumo 550 to the pilot lamp in the left headlight. It includes the XM receiver. There is room to get the power lead in the grommet in that light.
This is a switched source and if you want to power without the engine running, you can turm the switch fully CCW past the fork lock position. Only the tail light, the two pilot lamps, and the GPS (with XM Rx) will come on.
Thanks for the reply's guys, and the winner is the one in the head lamp,
because I don't wana have to feed a cable up to the handle bars, I hate effort :wink: