Google Developers Group
Last night, I was watching season 1 of "River Monsters" episode about Piraña -- the frenzy of getting the tickets had a close resemblance to the fish feeding frenzy.
Google IO is "the" conference for anyone serious about Android, GWT, GAE, Maps, Docs, search or anything to do with consumer-centric computer programming these days.
I was assuming that the conference will sell out in 3 hours, but I was wrong, it sold in 59 minutes.
Most "regulars" got an early invitation, but the rest had to be there right at the opening of the public registration and even that did not guaranteed the ticket, many got errors 503, some claimed to refresh the page 1000 times, which did not help things.
Some people got tickets 1 hr. 20 minutes after the opening, but they probably got luck as Google released few more tickets.
In any case, we can say the event is popular.
I am going, are you?