So we've got it on authority that the second-gen iPhone is already well into testing, and numerous units are floating around in super secret pockets. A trusted source got a chance to check one out, here's what we've heard.

The first thing people will notice: the 2nd gen iPhone will be about the same size and shape as the first gen.

It will, of course, have 3G. And proper GPS!

The most noticeable physical difference is back of the phone is no longer metal -- the whole thing is glossy black, from top to bottom. The volume buttons are now chrome.

Because it's got a little less metal to deal with, it doesn't have quite as many angular edges. The battery is (still) not removable.

The phone itself will be slightly thicker than the first gen device.

The headphone jack will no longer be recessed, and will finally be flush with the body.

The device itself uses roughly the same size and resolution screen as the first generation product.

No solid word on battery life or storage capacity.

It could ship (or be introduced) as early as July -- but it's worth noting that none of this is necessarily finalized, and any of it could change between now and its introduction. You really never know with Apple!P.S. -Image via iPod Observer , MacRumors points out it's probably just a case (which we'd likely agree with ); we're not by any means claiming the image above is the new iPhone, just an example of what it could look like given the info we received.