Vanilla KSP, take pictures. Drop a kerbal in a command pod (not chair!) from as high as you can on Kerbin (or the Mun if you're feeling lucky) without using parachutes, rockets, or wings to slow him down! Make sure to record the velocity you were at upon hitting the ground. I've been building "cages" around my command pods with different designs in the hopes that I can drop one at high speed without it killing the kerbal inside. For use when your decent stage blows up and you want to land on (insert astrological body here) without being rubble.