As part of its new lineup for the iPad 2, Bluetrek has released the LostDog Protecting Pouch ($40), a somewhat new take on the classic envelope. Made of a very soft microfiber, it's a sleeve with a fold over cover held in place by a leather tab. The case is made to work with the bare tablet, or with a Smart Cover. On the back there's an extra pocket for documents and the like. While Protecting Pouch doesn't include a lot of functionality, it does…