I get asked this quite a bit and people seem to forget more and more about the passcode, its just a simple 4 numbers in order to access your iphone I decided to make a tutorial on it. It's easy and requires the iphone to be jailbroken and have openssh running.
first copy the keychain-2.db from /private/var/Keychains/
Second get sqlite3 installed and run this against it
This will drop you to a sqlite3 prompt type in the following command
delete from genp where acct = "DeviceLockPassword";
Copy the keychain-2.db file back over the one on your phone and restart and poof you have the ability to reset your password up on the phone.
Thank you for reading.