How to Unlock Locked Phone using only MMC Reader. 
I used to act as a leecher For over 1 year, this is the time to post something usefull i think!

What phones do this trick work on?
It must work on all Symbian OS based phones.

What does this trick needs to work?
- The Locked phone (note the phone is locked not the sim).
- Memory Card (you can use the same locked phone Memory Card).
- A Memory Card Reader, or another sybmian phone with a file browser (FExplorer for example) installed on its phone internal memory).
- The MDL file (see attached file).

How to Apply the trick?
1. Remore the Momory Card from the Locked phone -if exists- or use your own memory card.
2. Copy the file "THC-NOKIA-UNLOCK.MDL" from attachement to the memory card E:\System\Recogs (if it's not exists, simply make it).
3. Place the Memory card back into the locked phone, the program should start in a few seconds (about 12 seconds for my 6680).
4. Now remove the memory card, restart the phone, the Lock is "12345" now.
5. You can remove the file, as it's not needed anymore.

How the goodness does this work?
It's more than simple, when phone is locked, it locks only the keypad, bluetooth, and the USB. So when u plug the memory card it starts the recognizers those inside E:\System\Recogs, then the file "THC-NOKIA-UNLOCK.MDL" does it's job by applying hard reset on the phone's software lock only.

Credits goes back to "The Hackers Choice" team: hxxp://thc.org.segfault.net/thc-nokia-unlock/