There's a company in Australia that makes cruise control for bikes, but it's not really electronic. It should work fine though. I priced it at around $1000 US, and a 2 person all-weekend job to get installed. WebBikeWorld.com did a review on it.
After all that, I decided that my $10 throttle lock wasn't so bad. I may even upgrade to the $25 version.
EDIT: BTW the issue with electronic cruise controls on our bikes is that our throttle isn't electronic. If you had a '05 or newer Harley you could just drop a $250 box in and have cruise control. I think the '11 Honda VFR has electronic throttle. Maybe one of the Ducatis. Beyond that, not so much.