Here's a way I do it.
Download a flashlight app for android. I used Flashlight for cupcake http://code.google.com/p/autosettings/
Use my hack to enable it to run in full screen or use my link here http://www.mediafire.com/file/jxnuln...forcupcake.apk
Now you can use the light from the lcd to read your eink display. It's a nice soft area light that no money can buy!