Well, someone had to do it: Available on eBay right now (and for another 4 days), 3 grams of Unobtainium, the ridiculously-named fictional McGuffin from Avatar. It even levitates, as an accompanying video "proves." Click through to see for yourself!
On the one hand, good for seller Pockyrevolution for coming up with a way to cash in on the James Cameron blockbuster. On the other, I wouldn't want to be them when IP laywers get involved.