Knives always come in handy for motorcycle riders. Not for fighting, but there's always something to cutoff from your bike, like strips of rubber, splicing electrical wires, removing strands of hay from your tires (honest, it has happened to me).
Here's an interesting knife, called "La Manette", that may help you. It's a knife in the form of your handlebar lever. It folds into the lever itself, so you can carry it safely with you. Just remember to pack it when travelling by air.
Availability: Now, but limited stocks.
Click here to buy the Handlebar Level Knife (in French) (Thanks Ian R.)