Most Hackable E-Reader

I'm interested in purchasing an e-reader of some kind (i.e. must use e-ink tech, no LCD screens) and wondering if anyone has any suggestions about which reader lends itself most to tinkering / extending / hacking? Are there any that make it possible to install your own software? (It would be cool to see i.e. Emacs running on one.) Nook Color, hands down. Unfortunately, your eInk criterion limits you to cheap knockoffs. If you're willing to go LCD, you won't be disappointed with a Nook Color. Cyanogen makes the ROM for it, and they are nearly impossible to brick. Heck, you can run a custom ROM right off the microSD card, never putting your warranty in jeopardy. And, because it's Cyanogen, you can read nearly anything, and have full Android Market access. -- Christopher Nook Color $249 Available from and manufactured by Barnes and Noble