In case you'd still like to know how to do it via fastboot, here are some steps:
Place the .zip in the same directory as the adb and fastboot executables
Double check the md5 of the .zip before proceeding to prevent bricking the device
I've been using this for about two weeks now, and I really like it. Thanks for bringing Omni to toro.
Haven't seen this mentioned yet, anyone having issues where the caller ID doesn't show the person's name until after the call is picked up? I can see the phone number but the person's name doesn't show up until the call is answered. Doesn't happen...
I could be wrong, but I'm pretty sure they are not kept. For purchased license keys, there is often a file stored somewhere that contains the key. For example, titanium backup creates a text file with your pro key in the root of your SD card.