The past few months have seen numerous signs that a PlayStation Phone is in the offing. They have ranged from not-so-subtle hints from executives from both Sony and Sony Ericsson to leaked pictures purporting to be of the device.

　　Today, though, came the most convincing proof yet that the PlayStation Phone is in the works. Video footage obtained by Tech blog Engadget shows the device, code-named Zeus Z1, being put through some of its paces by an unknown user. The soundless video shows the phone as having a PSP Go-like sliding form factor that produces a panel bearing a D pad and the four iconic PlayStation buttons. Between them is a touchpad with two buttons that appear to approximate dual thumbsticks. Dual shoulder buttons can also be seen on the edge of the relatively thick device.

　　The video also shows the unseen user interacting with a touch-screen menu of the PlayStation Phone, which is running Google's Android 2.3 "Gingerbread" operating system. Besides Gmail, YouTube, and Google Search, the menu clearly has a "PlayStation" button for games that is shaped like a DualShock controller. Unfortunately, the video does not show any games being played, nor does it indicate which games might be available on the system.

　　Today's video comes just over two weeks after photos purporting to be of a PSP2 development kit were outed. Those photos showed a similar PSP Go-like form factor, albeit with robust, full-fledged thumbsticks.