There is an open source project called Frotz
over at Sourceforge. They've got a number of Z-machine interpreters for various platforms, even the Franklin e-bookman. There are interpreters written in Java and Perl as well.
I've got the majority of the old infocom games (Activision released a couple of CD-ROMs with most of them a decade or so ago), so I'd be thrilled to see them playable on my Reader.
Like a lot of you, though, I'm completely lacking in the programming skills required to actually port something over.