Get a lanyard that goes around your neck - like you have at race meetings with your pass/ticket in.
You wear the fob around your neck so you don't lose it, leaving just the key in the ignition.
When you take the key out, clip it to the lanyard so you don't lose your keys.
Simple!
You could be really flash and get a Ducati one for 5.99:
http://www.grandprixlegends.com/Sale...Manufacturers/