Indoboard has been popular for quite some time now. Every time I would go to my friend's place I would use it. I have to admit that it is pretty fun but doesn't replace the real thing.
The Indo board consists of a wooden oval shape board and a roller. I feel it is a great tool to improve your balance and to become more aware of your feet: how much weight you distribute and those happy feet becomes more flexible, responsive as well.
So here is the thing to watch out for. I tried to do a ollie pop shov-it after an hour practicing on this thing. Obviously I didn't land it, ended up on my ass and the board went flying across the living room.
my two advices: do it on a carpet so that if you fall, you don't hurt your self. Then remove any furniture around (particularly if there are made of glass).