Mate,
If you don't have a master key then you could remove the petrol cap and take it to a key cutter and see if they can find/grind out a match cos its the same lock as your ignition.
A few years ago at a WSB round at Brands my mate lost his zx-7r keys at Dingle dell somewhere. After much hunting we gave up but luckily there was a locksmith on site and he did just what I have mentioned above. At 10p.m. in the middle of a field with a head torch and a file. Top bloke.
What a sight we were - 2 bikes in the middle of a dark field - everyone else had long gone...
Then I had the pleasure of riding all the way home to Swindon on an M600 with a dark visor
Jacko.