Have you modded your Galaxy Nexus a little too much? Do you have the boot loop blues? Google is here to help with an official Galaxy Nexus image.
Flashing the image will wipe out your Nexus and return it to it's original, stock state. You can get your factory fresh copy of Android 4.0.1 right here. The archive contains the bootloader, baseband, and the system files.
Install instructions are the usual ADB shenanigans, full details from JBQ himself can be found here.
Good luck! Oh, and if you can't get your Nexus working, I'll be glad to...