"Wiping" a BlackBerry removes all user data from the phone, returning it to the factory settings. You cannot recover data from a BlackBerry wipe; when you remove this information, it is permanently gone. However, if you make a backup file before you perform the wipe you can use that to restore data to your phone.
Turn on your BlackBerry phone before you and connect it to your computer. Then start the BlackBerry Desktop Manager program. (It comes with your phone but if you need to download it again, you can do it from the Research in Motion website; see Resources below.)
Click "Backup and Restore" and then click "Backup" on the next screen. Follow the screen prompts and then wait for the BlackBerry Desktop Manager a copy of your files. Disconnect your BlackBerry phone before you perform the BlackBerry wipe.
Reconnect your BlackBerry phone to the computer after you finish the BlackBerry wipe. Open the Backup and Restore Wizard again. This time click "Restore" and follow the on-screen prompts. Be sure to choose the same backup file that you just made to restore the data. You will see a confirmation message when the process is done.