Google's nearly four-hour I/O 2013 keynote is yours for the watching on YouTube

Looking for some entertainment on an upcoming cross-country flight? That might just be the only reasonable excuse for sitting through all 3 hours, 51 minutes and 25 seconds of Google's recorded keynote. The I/O presentation, now available for playback on YouTube, covers many of the company's announcements from yesterday, including All Access, Hangouts, a bounty of developer tools and that Galaxy S 4 running stock Jelly Bean that we weren't expecting to see. All that and more can be yours if you ...