Tinhte

Apple may have killed off its last white plastic gadget with the recent shelving of the unibody MacBook, but an alleged iPhone prototype that's making the rounds suggests it could be making a comeback.

Macrumors today picked up on a forum post from Vietnamese site Tinhte--the same outlet that got ahold of the iPhone 4 ahead of its official announcement, and more recently a 64GB iPhone 4 model--with what it says is a new variant of the iPhone 4.

What's new? The translated forum post says the device is a little bit faster than the iPhone 4, weighs less, and is sporting plastic on the front and rear instead of glass.

That last bit is where things get interesting. Apple nearly shipped the original iPhone with a plastic screen, before changing it up to "optical-quality glass" just ahead of release for what the company said would result in a "superior level of scratch resistance and optical clarity." That Apple would be contemplating a step back to plastic based on that claim is worthy of some eyebrow raising.

Numerous reports suggesting Apple has been working on an upgraded version of the iPhone 4 instead of a brand new model go back to May. (See CNET's iPhone 5 rumor roundup for more.) More recently the tide has shifted, with rumors suggesting the release will represent a new generation with a different design. That was strengthened earlier this week with an alleged iPhone 5 case design with room for a larger screen and a return of a curved back, a design feature that stuck with the phone through its first three iterations.

As noted in previous coverage, a move to offer two new versions of the iPhone would represent a dramatic departure for Apple. With recent annual releases, Apple has simply continued to sell the previous version at a discounted price, as it does now with the $49 iPhone 3GS. The poster of this allegedly plastic variant of the iPhone 4 suggests this newer version will in fact represent the lower-cost model that will sit alongside the iPhone 5, an idea that's been kicking around since after the release of the original model, and cropped up once again at the beginning of this year.

Why make a lower-cost model? To help fend off competitors like Google and its army of Android phones. According to a Nielsen research report this morning they are up to 39 percent of the smartphone market in the U.S., up from 29 percent in March.

Later this year Apple is widely expected to take the wraps off a new iPhone to replace its now more than 1-year-old iPhone 4. A report from earlier today suggested Apple was cooking up a production test run of 400,000 units ahead of beginning mass production for a release in September.