Google has announced that its increasingly popular Google I/O conference, which this year sold out in 59 minutes, will be lengthened from two days to three and moved from May to June in 2012.

Google I/O 2012 will be held at Moscone Center West in San Francisco on June 27-29. Earlier this year it was also held in San Francisco, on May 10-11.

Google, like Apple with its always-sold-out Worldwide Developers Conference, is a bit secretive about Google I/O particulars, setting up a real race once registration details are revealed. Registration for the 2011 Google I/O event took place in February.

Monica Tran, from the Google I/O Team, blogged that developers should stay tuned to Google's developers page on Google+ to be the first to know about Google I/O registration. In addition, Google is urging developers to "brush up on your coding skills" for a chance to win tickets to the event.

For those who need to pay to attend, Google this year charged $450, or $150 for students/faculty, plus an extra $100 for a bootcamp programme.

In recent years when popular tech conferences have sold out quickly, tickets have then surfaced on sites such as Craigslist and eBay. Google I/O tickets this year were bid up as high as $2,000 on eBay, four times the face value.

Sessions at this past May's Google I/O included everything from "Storing your data on Google's cloud" to "Building Web apps for Google TV" to "Honeycomb highlights." Google Earth, Google Apps and App Engine were among the other topics on the agenda. Google used its conference this past spring to highlight an expansion of Android as a platform across all device types.