[BookCat]

I used to know someone who had an old gameboy (the type which had only one screen and folded out like a tiny laptop). He used some kind of emulator to put PD text format books on it. This was before ereaders existed/were popular, and was the reason why I took so readily to the concept of an ereader.

His device was about the size of a powder compact, though square. You could probably still buy them second hand from ebay, but I don't know how he used the emulator to get the books onto the device. I'm sure there are techies on MR who could tell you how to do this.

It was a great little device designed for playing games. Unfortunately it was led backlit (I think).

Edit: I think it was a Gameboy Advance SP.