Stan Lee could have had a much more amusing cameo in Marvel's Guardians of the Galaxy if Disney hadn't forbade what director James Gunn had originally pitched. During a panel at Dragon-Con, Gunn revealed the concept of what that cameo would have been, and it was so much better than we we ended up seeing. The following info comes from Collider:
"One of the losing battles regarded Stan Lee's original cameo in the film. Originally, Gunn had planned to have Lee in one of the Collector's exhibits. Groot would then look at the exhibit aghast, to which Lee would flick off the large tree creature."
That would have been freakin' hilarious! Having Lee in The Collector's collection is such a brilliantly fun idea. I guess the reason is didn't happen was because it was too similar to the flipping off joke with Peter Quill and Nova Corps. The movie was still great though!