I participated in the "Give One, Get One" campaign where I bought one and donated one. I used it to read my email for a while - it was super slow but I enjoyed the novelty. It used Sugar OS which was their own Linux flavor (I think).

I was a bit naive about the whole project - I heard Negroponte speak at an event where he was arguing defensively that all a country needs is technology (even ahead of civil society) and I was so disillusioned. I was no expert in this area, but his arguments were very weak. Pretty disappointing and I feel bad for the really kind and generous people who poured so much of their time into this project because it had garnered so much goodwill.