According to an unconfirmed report, Apple, Inc. is developing a mobile computer larger than an iPhone but smaller than laptop or tablet PC.

Seeking Alpha cites unnamed sources when it says Apple is prepping a device with a 5.2-inch, 800-by-480-pixel touchscreen. This will supposedly have a landscape orientation, and be held by the the user between their hands.

It is not expected to have a hardware keyboard; instead it will depend on a virtual one, as the iPhone and iPod touch do, with the user entering text on the screen with their thumbs.

Details are very sketchy at this point, and there is no word on whether this model will run the embedded version of OS X as Apple's handhelds and smartphones do, or the full version of this operating system.

This device will reportedly not be the tablet PC that Apple is also rumored to be working on. That model is expected to have a significantly larger screen -- 7 to 10 inches -- and will likely run the full version of OS X.

It is not known when Apple will introduce this portable device, but Seeking Alpha says it is probably still on the drawing board, and therefore is likely targeted for release late next year.