Amazon still working on two smartphones, one with a 3D interface, says new leak..

We’ve been hearing about an Amazon-branded smartphone for more than a year now, however the company has concentrated its hardware efforts on the Kindle Fire tablets, culminating in the new HDX models announced earlier this month. The rumors have continued to spread regarding a phone though, with varying reports arguing about whether the resulting device would be free or not. We’ve even heard talk about Amazon experimenting with 3D technology.

The latter rumor has now popped up in another leak, after an anonymous poster wrote about Amazon’s plans on the Hacker News forum. The post, entitled, “Insider’s details about the Amazon Phone,” is far from official, but TechCrunch has since confirmed some of the details with its sources, lending it some credibility.

Apparently, rather than being a full-on 3D phone like the LG Optimus 3D, the device – codename Smith – will feature a 3D user interface. This doesn’t sound very exciting until you hear it’ll operate using four different, corner-mounted cameras to track head and eye movements, so you can navigate through screens and peek around corners to see alternative controls. The front cameras would also ignore faces on the edge of the screen (mates looking over your shoulder, for example), and the rear camera may use object identification to scan and search for the item in Amazon’s own store.

However, a phone with five or six cameras (four for the eye-tracking, and potentially two regular lenses) could make the Smith an expensive phone, and that’s before adding in the development and implementation of the 3D UI. So, Amazon may release a second, cheaper phone to go along with it. Codename Project B, it could use a similar, scaled down version of the Fire tablet’s operating system.

Amazon’s plans to release these two smartphones have been scuppered by staff leaving the company, engineers being moved to other projects, and extended testing of the software and hardware. This has resulted in the release date being shifted around, and it’s still not clear if either will be announced this year.