The newly-released Lenovo Folio case is a gem, but alas, only functions with the ThinkPad Tablet.

ENGADGET: Ask Engadget: best wireless keyboard for tablet use?

The Boogie Board Jot Folio is a leather-like case with a convenient flip-over design similar to a traditional stenographer notepad.

ENGADGET: Boogie Board Jot eWriting pad hands-on (video)

Designed to provide a better typing experience in a smaller package, the Belkin Portable Keyboard Case combines a removable keyboard and convenient folio in one slim, lightweight design.

ENGADGET: Belkin bulks up iPad mini with $80 Portable Keyboard Case