[MOD] Unsecured boot.img for 2.1 (3.0.1390) Tester ROM
(Also posted at the end of j_r0dd's original thread)
Here is an unsecured boot.img I made from the Moto 3.0.1390 tester rollout if anyone needs it. It's in update.zip format, but if you really want to flash it from the command line, simply extract the file boot.img from the zip and you can also do it that way. In which case, do "flash_image boot /sdcard/boot.img" or such, depending on where you put the file.
It disables ro.secure, and enables ro.debuggable and ro.adb.persist, so root stays on your phone after reboots (as far as I can tell) and ADB always gives a root shell..