And just for completeness, here's how to add root/superuser access to the stock ROM.
I actually did this in a roundabout manner as I was learning, but here I'll list the simple version that should
work. If not let me know and I'll try and recreate the full version.
EDIT: After some feedback I have changed the instructions for step #4 and added #5 and #6. (They used to be all one step in recovery mode, but the apk install doesn't work that way.)
1. Download the Superuser archive here
and unzip it.
2. Boot in to the recovery image and connect the USB cable.
3. Have the recovery image mount the filesystems. (There may be errors. Ignore.)
4. In the new Superuser dir run the commands
adb push bin/su /system/bin
adb shell chmod 4755 /system/bin/su
5. Reboot in to normal mode. Enable Non-Market apps and USB debugging (default off in this ROM.)
6. In the Superuser dir run:
adb uninstall koushikdutta.superuser
adb install bin/Superuser.apk
The uninstall command should fail of course.
Now try running an app that requires root access and the Superuser Whitelist should come up and work as expected.