How to disable Verizon's future OTA updates
To turn OFF future OTA updates, there is a file in the /system/etc/security folder. The file is named "otacerts.zip". Rename it "otacerts.zip.bak", or whatever you want. That will prevent future updates.
You can change that filename using ADB, the root explorer app, or a terminal emulator app of choice right on your DROID. I use root explorer because it is easy and fast. But that's just me...
Using Root Explorer... If you are using Root Explorer to do this and it says "the file system is read only" Just touch the white button at the top that says "mount r/w" and then try it again.