Stalter press or press to handstand. Hands flat on floor or beam. Assume straddle with butt and legs off surface so all weight is supported by hands. Now press backside up in pike and then take legs up to handstand without touching floor. From handstand you can return to straddle support and repeat as often as possible/desired.
If you want to learn it, have someone stand facing you, then reach over and guide your hips as you press them up. They can guide them down as well so that you don't bounce down and hurt your tail bone.
http://www.mspt47.com/gymnastics/ind...ess_Handstands
http://www.youtube.com/watch?v=GBGm1w6s8xQ