Mozilla announced a while back that it would start selling Firefox OS Developer Preview phones sometime in February. That obviously didn't happen, and there's no mention of when the phones will be widely available to developers. Until then, you're best chance to get one is at one of Mozilla's recently announced workshops.
Mozilla announced today that it will be hosting a number of Firefox OS App Workshops starting in April. The first will take place on April 20 in Madrid, Spain; the second on May 18 in Bogotá, Colombia; and the third on June 1 in Warsaw, Poland. Mozilla says that it plans to have more workshops in more locations later on in the year.
So, what will those attending the workshops receive? Mozilla says it will be offering the usual free swag, like t-shirts, and a free meal to all attendees, but the real treat is that all those in attendance will receive a Firefox OS Developer Preview phone.
All Mozilla asks is that those wanting to attend have "solid ideas and strong Web development skills." In other words, it's looking for developers who have built apps using open Web development platforms like PhoneGap, Chrome, webOS, BlackBerry Webworks, etc.
Those attending can also look forward to working one-on-one Mozilla's own Firefox OS development team to create new apps for Firefox OS or port an existing app to the HTML5-centric mobile OS.
If you wish to attend, you'll have to apply for a spot at one of the events. Mozilla says they'll be approving applications on a first-come, first-served basis.