I came across this on CNN, the SIM:SLurl Second Life now has a Pandorian world added.
Here is the website: http://slurl.com/secondlife/Pegase/174/144/3948
Join up create your human looking character. Once you get into the SIM select search and type in Pandora. Select the very top Pandora-Avatar link and then teleport into Pandora. I didn't stick around long as the graphics for this PC are only basic motherboard graphics. But the SIM does look promising however.