re: Prank in space.
On one of the Hubble servicing missions (possibly the previous one) - one astronaut was deep inside Hubble and had to pass a pipe or cable thru an opening to the other astronaut working under Hubble. It might have been something to do with the Nicmos cooler, but I may well be wrong.
In the NBL, he would often poke the cable thru, only to snatch it back when the other guy reached for it...it became their practical joke.
And yup - he did it on orbit.