Engadget has photos of what it says is a prototype Sony Ericsson slide-out phone with PlayStation-PSP–style gaming controls. The phone has a multitouch trackpad (it’s hard to slide analog sticks beneath a screen) and purportedly will appear sometime next year running Android 3.0, aka Gingerbread.

Rumors of an Android 3 PlayStation Phone first emerged in August. But we’ve been down this road many times before, with devices reported to be imminent, then killed off.

According to Engadget, the phone’s screen is “in the range of 3.7 to 4.1 inches” — they have photos, but not a copy of the phone itself, so there’s some guesswork involved. The phone is also reported to have a 1-GHz Qualcomm processor, 512 MB of RAM and 1 GB of ROM.

That’s not much storage if the phone’s going to store games, pictures, video, books, apps or other media. Apparently the phone takes microSD cards but not memory sticks or UMD. That’s one way to solve the storage problem, albeit a cumbersome one.

Engadget also claims there will be a special Sony Marketplace offering Android apps for the device. Custom Android app stores for custom Android devices seem to be the thing to do: Barnes & Noble is getting ready to do just that for its new Nook Color.