The trick commonly works with Internet enabled mobile phones. Works Fine with symbian and java. Follow the Steps:
1. Download any of “File explorer” software in your mobile
eg. FExplorer in symbians
2. Insert the memory card to phone and do not access it.
3. Open Explorer and locate the file mmcstore and rename it to mmcstore.txt
4. Connect the phone to PC and open {mmcstore.txt} file using notepad
5. Your forgotten password will be somewhere in textfile.