what exactly is the phonedmg good for

[ntpphong]

I unlocked a few phones but i never had to create that folder?

[Eurisko]

I unlocked a few phones but i never had to create that folder?

That folder isn't used for unlocking iPhones, it was used for jailbreaking them.

[robbpell]

that was used in the early stage of file transfer to and from you iphone! before ibrickr and ifantastic you had to put any file you wanted to put on your iphone there and use a cmd prompt to move the file to you iphone