I'll assume by now that you've seen James Cameron's Avatar (and for many of you, more than once). If not, call in sick tomorrow and go see it (in 3D; Imax optional, but not 3D). After you have, then pop over to the Fox Screenings web page and grab the free PDF copy of the screenplay.
There are a number of other Avatar related items at Amazon - video games, the Soundtrack, a children's adaptation, The Na'vi Quest for $4.99 and a coffee table book ($17.51), all on the Avatar products page. There isn't anything out on Kindle, and no pre-order for the DVD/BluRay yet (when there is, I'll probably have my order in the first day), so the screenplay will have to hold me over until then.