(I've copied this thread from the Transalp forum as suggested by one of the replies, so sorry If you've read it already)
Here's something I've done with all my bike keys which I thought I'd share with you lot. If like me you have more than your ignition key on your key ring then this protects you yoke/ignition paint work from chips and scratches.
I've used small pieces of 'heat shrink' to cover the keys, attached to the key by some thin cord. When you need the key, you simply slide off the 'heat shrink' and then slide it back on after. (the cord stops you losing the heatshrink).
Be careful not to shrink the heatshrink too much or it won't slide off.
I use coloured 'heat shrink' so I can tell the pannier key from the top box one. The other key's for a lock.
(For those not familiar with 'heat shrink', it's used in electronics to insulate or hold together wires. It's basically a tube (like a straw) you place over wire and when you heat it up it shrinks to a tight fit. Its available at places like Maplins, a couple of £'s for a meter length).
Hope you might find that useful.