I have some type of actual (not the throttle lock kind) cruise control in a box that was removed from my bike by the last owner. The original owner installed it, but the 2nd owner said he didn't feel like you should have cruise on a bike. I never did anything with it as it doesn't really bother me either way. I'll probably add a vista cruise, though.
I've been using the Throttlemeister on now my second bike. Some don't like the way it functions but I've always found it nice in that it's adjustable and not either on or off. You can modulate it if you see you're catching up to traffic or similar situation. www.throttlemeister.com