Just so someone reading this wont have to read all of the crap in Belgum Waffles' thread. His son was not cited for violating the Oregon code that deals with sitting on a bike, he was cited for careless. Yes, I think it was an improper charge, proper stop, but in the spirit of the law, the wrong code was used.
As for other states etc, look it up on the web or stop by your state police office and ask them. If your state forbids it, just remember to use a reasonable argument if you go to court. Simply stating your bike is designed for it and you were in control does nothing to negate the issue of your butt not being on the seat. I would suspect you would have to do better than that. A Ferrari is street legal, can do zero to god knows what in a blink of an eye, but does not make it legal to actually do it. "But officer, my car was designed for this" won't get you any where.
That all being said, ride safe and enjoy.
04 R1150R - sold
07 R1200GS - sold