I also watch Julio a lot... especially in the mornings when I have my breakfast (this generally makes me late for work - hes such a distraction!!)
He loves being watched too, and he gets really excited and dances around... he also loves it when I click my fingers at him... he goes crazy!
Not sure what that's about but he really responds to it.
This morning he was flaring and showing off a little bit

I switch his decorations in his tank up once every 6 weeks or so just to keep him on his toes...
As for the ping pong ball - he flared at it when I first put it in etc, but he then ignored it... ill pop it back in tonight and try and get him to play with it...
I keep my tank in the kitchen as its more of a high traffic area. I think he likes all the action that goes on...hes a bit of a sticky beak too... the other day I caught him laying on his hammock just watching me and my husband making dinner!