Are we talking like Razer's concept from a couple years ago at one of the tech shows (CES? I don't remember, honestly) or something like Acer's Iconia dual screen tablet/notebook?
I had the Thinkpad W700 with the pop out side screen, not to mention the wacom tablet built into the right of the touchpad. It was a great parlor trick, and genuinely useful for running a terminal or a music player to the side of your main workspace.
They demoed it and apparently the unit they demoed was stolen when they were leaving the show.
Not going to lie, I’d love an Acer Iconia style portable at this point. Wouldn’t use it for desktop publishing or probably anything with heavy typing, but just seems like a fun form factor.
[0] https://www.engadget.com/2009/01/26/lenovo-w700ds-laptop-rev...