I got a free nJoy King. The thing was nearly identical to a real cigarette. But I killed the battery in 2 hours. At $9 a pop I don't think it's a purchase which could keep anybody off of analogs. The technology is really cool though.
The next smallest e-cig on the market next to the King is the
joyetech e-roll. I got my brother one for Christmas and he's been using it ever since. I don't even think he's using his eGo twist and Vivi Nova setup anymore. That would be the only mini I would recommend. I tried the e-roll before I gave it to him and I almost ordered one for myself. It's not nearly as good as my normal set up, but if you're on the go and trying to be discrete it does the trick. It's tiny, has an auto draw switch, a 1000mah pcc(which charges the
batteries fast and will last all day), and is light enough to dangle from your mouth. Definitely worth checking out imo.