Two weeks ago, 1/25/12, we decided to quit for good . We have been encouraging him for months to stop on his own. We went to Build A Bear and built a very cute monkey, it helped, but didn't get the job done. So, I put some gross tasting nail polish on his thumb and then we bribed him. He will get a prize every day for a week and if he can go for an entire month we can go to Great Wolf Lodge.
Elliott told me that he was "okay" with not sucking it anymore. For the first few nights I would see him bring his thumb up to his mouth, hover around, then bring it back down again. It has now been two weeks and he is doing great.
On the other hand, Holly, who has been totally hooked on her pacifiers is starting to munch her thumb when the paci isn't around...let's hope it's teething.