Google's mega-popular Android and software conference Google I/O is scheduled for June this year in San Francisco, and registration is open right now. If you want to get tickets to Google I/O, run, don't walk to the registration page, and have your Google+ and Google Wallet accounts ready. Google I/O is always a sellout event, thanks to sneak previews at future Android versions and features, great workshops for developers, and (last but not least) the prospect of free giveaway gadgets.