After having both of our Honda 2000's stolen on the way to Quartzsite a few years back we did some research on a better way to secure them than with a cable and lock.
Check out the pictures on Photo Bucket. The cages we had made are very similar to the pictures. When the generators are not secured in our truck they are secured to the front jacks of our Monty.
While we realize that nothing is safe, we are hopeful that our cages will slow down the thieves long enough for them to realize it's not worth the effort.
http://s1086.photobucket.com/albums/...or%20Security/
We'll be taking some pictures of our setup as soon as we start packing for Quartzsite. If anyone is interested we'll be happy to upload them also.