Look like most of the people writing hacks learned in the same way.

And i think that is the best way to learn it also.

But there are more to php than writing hacks.
Its a good way to start of course.

Its a good way to learn php code but the vBulletin source is a far cry from showing you everything that can be done with php. I started that way to tho, and had done my fair share of lurking php.net ;).

If your are going to learn via code written by others don't limit yourself to one source. Anytime I see a script coded in php for download I grab it and fire up good old editplus (which most of the time is running in the taskbar anyway ;) ). The only problem with learning this way is you can pick up some 'bad coding habbits' depending on the source you learn from.

O yea word of advice to people who might be intrested in learning php. I have never seen an online tutorial come close to covering php as well as books have. I always recomend getting a good book over reading a tutorial via the internet for the newbie. Online tutorials still have their place tho, they come in handy after you have a basic grasp on php. And unlike a book they can be online at the authors whim, where the book takes awhile to print and publish.