Hm, yeah, the headstand seems to be a similar idea. Running with the sandbag on your noggin will obviously have a bit more impact though, since it's not static, and static sandbag holds would provide you with two additional things: 1. the potential to go really heavy, 2. a stability challenge (if you go hands-free... I don't think a hands-free headstand is possible for most people).
And yes, I'm actually holding that handstand. Get on my level.