I just got an email from Enterprise saying they now rent motorcycles on the vegas strip... prices look reasonable too.... $400-$800 a week.
http://www.enterprise.com/car_rental/deeplinkmap.do?bid=056&dcpCode=MCYCLES&TLGOff=301600001t18&arc=EUSEEC2&cm_mmc=Email-_-RentalLoyalty_EE-_-20141014_EUSEEC2_301600001t18_X_X_X_X_X-_-211050025_1208369
http://www.enterprise.com/car_rental/deeplinkmap.do?bid=056&dcpCode=MCYCLES&TLGOff=301600001t18&arc=EUSEEC2&cm_mmc=Email-_-RentalLoyalty_EE-_-20141014_EUSEEC2_301600001t18_X_X_X_X_X-_-211050025_1208369