the key is making *vroom* sounds.
take some pink dumbells - one in each hand should do.
then just do windmills and run around the gym.
remember, the "vroom" is key.
also, go up to a recumbant bike and lay down on top of it so that your legs are hangin goff the back of the seat, your chest is arched down over the seat, and then your hands are on the pedals.
you can then either pedal with your arms, or just smack them and moan - either way is effective.
either way, the moaning is key here.
also situps - those get the inside of the arms nicely.