Which books allow you to bet box office gross?

I i've seen topics here and on twoplustwo where people are betting on box office gross for movies, and i was wondering what books everyone uses to do so.  I can do it at sportsbetting but only every now and then on a largely hyped movie like pirates 3.  I know pinny does it but i don't have that option as i am in america.  I have emailed the greek and wsex and they say they no longer do it. 

 

So i was wondering if there were any highly rated books that still did this?

 

Thanks

MP

rock island