Salamba Sirsana, King of all Asana, the Headstand. I haven't been doing enough of them lately, but they are so much fun when I do. Why? Because you get to be upside-down. The boys seem to spend at least a third of their time throwing themselves on the floor, heads down, butts up the wall/the back of the couch/the edge of the ottoman. Hilarity ensues. Gales of laughter. The baby does a sort of free-form Uttanasana meets Down Dog, and looks around at it all from that perspective.
A friend asked for my thoughts on her new teaching space: a conference room in a skyscraper with panoramic views out a wall of windows. How did I think she should teach headstands, so as not to disorient her students? I gave it some thought--I didn't want her to lose anyone. But it seems to me the whole point of a headstand is to disorient. You're upside-down, you're inverting your whole body, gravity pulls on the opposite end, blood rushes away from the feet towards the head. If you accept this topsy-turvy situation, it can be very freeing as you watch birds fly under trees and an ant scurry upside down past your forehead (hopefully, that won't make you lose your balance).
It's a treat and a trip to go head over heels. Make sure you cushion the top of your head and don't rush to get away from the wall. If you need the support to feel safe and comfortable, use it. If kids love to do it and do it repeatedly ad nauseum, it's got to be fun.
Embrace the new view and look around--who know what you'll see from this angle.