I've been doing it for about 2 years now, and in that time, I've probably seen another guy filming himself on 2 or 3 occasions. So, yeah, its pretty much just me.
I've had a couple guys get really curious when I set it up (just my iphone clipped to an alignment rod speared into the grass) and come up to me and ask "what is that thing?" "Uh, its ... an ... iPhone."
They are very disappointed. Thought it was some sort of launch monitor or something. ;)