The 3G OLPC Laptop
That's three grand, not third generation. A (possibly biased) report by Vital Wave pegs the 5 year TCO of the OLPC at $2,700. That's even more than my estimate of $972/laptop from back in 2006, which got me in NewsForge and called a racist child-hater in Slashdot.
More discussion over at OLPCNews.com