Avatar: The Game for PSP will be able to communicate with the PS3 version or the game, according to reports.
Sounds like another Ubisoft title you may have heard about. Assassin's Creed 2.
Anyway, one of the features is the ability to transfer "Effort Points" from PSP game to PS3.
According to the October issue of PlayStation:The Official Magazine, the PSP version has players taking on the roll of a Na'vi warrior and these "Effort Points" transferable through both games will give your characters a bit of a boost.
More should be revealed when the new issue lands.