Our friends over at Gizmodo have gotten their hands on the fourth-generation iPhone prototype. They've spent a whole week with the unit and even taken it apart. Keep in mind Apple hasn't even announced a fourth-gen iPhone yet, let alone talked about it.

Over the weekend Engadget posted some photos of an iPhone-resembling device that was apparently found on the floor of a San Jose bar. Pretty suspect, but then the editors at Gizmodo this morning posted a huge dissection of that very device (possibly prompted by Engadget's article), which they say they've had for more than a week.

With the checkered past of this story out of the way, what's the deal with the phone itself? Here's what the Gizmodo crew found:

Gizmodo's verdict is that it's the real deal. From the leaked images, the new iPhone will sport a glass back panel (possibly derivative of a ceramic enclosure Apple patented back in 2006 that is radio transparent). Also prominent: a front-facing camera that would be handy for video chatting. The usual camera at the rear now with a built-in flash. The SIM card has been replaced with a MicroSIM, and the screen has higher resolution.

Those are some impressive upgrades, but the thing that gets us most excited is the front-facing camera. If Apple can pioneer a new feel for the iPhone (glass would certainly help) and be the first to bring mainstream video chatting to America's cellular masses, that'd certainly help put the iPhone back on the map at a time when worthy contenders are starting to hog some of the limelight.

Here's a more detailed breakdown of what's new in the next iPhone:

• Front-facing video chat camera
  
• Improved regular back-camera (the lens is quite noticeably larger than the iPhone 3GS)
  
• Camera flash
  
• Micro-SIM instead of standard SIM (like the iPad)
  
• Improved display. It's unclear if it's the 960x460 display thrown around before--it certainly looks like it, with the "Connect to iTunes" screen displaying much higher resolution than on a 3GS.
  
• What looks to be a secondary mic for noise cancellation, at the top, next to the headphone jack
  
• Split buttons for volume
  
• Power, mute, and volume buttons are all metallic

Via Engadget and Gizmodo