It's called the Monarch chair, made by ALITE. It's pros: super lightweight, packs down to "burrito" size, it's cool looking, and balancing on the two legs can be fun. The cons: It's smaller than it looks in photos, it's not cheap (mine had a $59 price tag on it), and, balancing on two legs can suck (especially after a few drinks).
I bought it as an alternative to the mountain chair that Cane Creek popularized years ago and is now duplicated by EMS and Thermarest. They are both very low-profile, but the Monarch chair gets you off the ground, which can be handy if it's wet.
After getting a chance to use it at a concert last night, John Mayer at SPAC (masterful playing and good backing band almost made up for the awkward banter), I can say I am happy but not totally satisfied with the chair. I would still recommend the Thermarest chair as an alternative in its class. I figure for the avid camper, the Thermarest is more versatile. It can be used as added support along with a sleeping pad or can be used as a pillow, and can also be a back saver when spending long periods of time in a canoe. I don't think the Monarch chair would do well in a canoe.
So there you have it. Hope that helps make your decision easier.