Update: Tickets appear to have sold out in less than 30 minutes. More here.

Google has opened registration for its annual Google I/O developer conference, this year extending the event to three days from its usual two.

Commencing on June 27 through to June 29, 2012 at Moscone Center West in San Francisco, a ticket for Google I/O will cost $900 for a general attendee and $300 for students and faculty of schools.

In a very Google-centric move, you will have sign up for a Google+ account (if you don’t have one already) and will have to pay with Google Wallet — streamlining the registration process for the company and ensuring that it doesn’t have to rely on third parties.

Wondering if the event is for you? Google breaks down who will get the most from its I/O conference:

We recommend that web, mobile, and enterprise developers building applications in the cloud with Google and open web technologies attend Google I/O. Products and technologies to be featured at I/O include App Engine, Android, Google+, Google Chrome, HTML5, AJAX, Maps and Data APIs, Google TV, and more.

Google expects 5,500 people to attend this year’s event, and with the conference selling-out within an hour of the tickets going live in 2011, we recommend you be quick.

If you’re curious about Google I/O 2011 everything you need to know is here and you can be sure that we’ll be there this year to bring you all of the news again.