This write up is to guide people who have moved on to other phones but what to use their good old Droid X for a wifi device. Many people have just frozen or uninstalled the dialer and messaging apps, but this is going to an unnecessary extreme. Other people have used airplane mode, but this is a pain because it also disables your bluetooth and wifi. Sure you can toggle them back on, but this doesn't persist after a reboot. This fix allows you to use airplane mode to disable the cell radio, but not the wifi or bluetooth. The extra benefit is that you still have a fully functional phone if you ever need it as a backup.
Step 1. Download a File Manager from the market that allows browsing as root. I recommend ES File Explorer because its free and has a search function.
Step 2. Open the file manager and go to its settings. Find any settings that allow you to browse as root, navigate to the root of the filesystem, and mount the filesystem as rw (Read & Write). If you get a Superuser prompt, click allow.
Step 3. Navigate to the root of the filesystem. If you see folders like "etc" and "system", you are there.
Step 4. Use the search function to find settings.db. On ES, make sure you are searching the current folder and have the filter set to all files. Enter settings.db as the file name.
Step 5. Copy the settings.db file to your sd card. Note the directory you found it in. Usually /data/data/com.android.providers.settings/databases.
Step 6. Download SQLite Manager from the market. Open and navigate to /sd card and find your copy of settings.db. Click on it.
Step 7. Click on "system" and then long press on the line that says "airplane_mode_radios". Click on update row and edit the value so that it only has the word "cell" in it.
Step 8. Back out to update the file. Re-open it in SQLite Manager and verify your changes. If your changes did not stick, keep trying.
Step 9. Copy the settings.db that you edited on your sd card back to the folder you originally found it in. When prompted to overwrite, allow it.
Step 10. Reboot and turn your wifi on and activate airplane mode. You wifi should stay on. Reboot. Your wifi should come back up right away but airplane mode should still be active.
Edited example settings.db from .605 stock in a zip file. This is not flashable in CWM Recovery! You can use this but it will probably change a bunch of settings back to what they are when you first set the phone up. Better to sbf and then apply this right away before changing any settings.