As part of the continuing theme of do-good at Web 2.0 Summit 2008, Lance Armstrong, unretired cyclist-cum-philanthropist extraordinaire, took the main stage as the dinner keynote. This was the only appearance he agreed to honor after announcing his cycling comeback and his visit was much anticipated. It didn't disappoint.

Summit co-host John Battelle joked with Armstrong about pulling a Brett Favre, and Armstrong took exception, quoting LL Cool J ("don't call it a comeback, LL"). Armstrong was challenged about his reaction to the election, given his close proximity to the current president, with whom he's been cycling ("I kicked his ass," Lance gloated). And he was asked whether he would accept an appointment as Cancer Czar if the new president named one (he politely sidestepped).

But Armstrong's purpose on stage was as clear as his desire to race again. Although he believes he can win, he wants to continue to raise awareness and money to fight cancer.

There were a few loose technology tie ins: He has recently started Twittering (only 10 days into it and eager for followers); and had some things to say about using social networks to drive change in diet, fitness, and lifestyle; he also took a shot at Broadcom's ex-CEO Henry Nicholas.