World’s best Mac OS X reversing tutorial for newbies (or maybe not!)

Things are a bit slow around here. GMAT is taking most of my free time and day job been busy. Last week I had some free time and decided to take on this small project.
By popular demand here it is, a long tutorial explaining how to reverse/crack a Mac OS X application, starting with tools (GDB and otx) and then a step by step of how to crack a time trial protection.

Writing such tutorial is not an easy task, trust me! It’s not easy to explain things you know now by instinct and translate them to words. I did my best and it should break some ground, making things easier for those who want to come to Mac reversing world. I think the most interesting part is how to work with GDB, which should be the hardest part for anyone coming to Mac OS X without any experience with it. It is assumed you have knowledge about x86 assembler (there are already too many excellent tutorials about this).

If you have any comments, improvements, errors feel free to leave a comment. All help is appreciated.

The target app is SlidePad. I leave here the binary I used so everyone can follow the tutorial and not have problems with different versions.

Here are the files:
beginners-tut.txt
SlidePad.dmg (SHA1(SlidePad.dmg)= 6d85814fd69fd82ac23a40fd16e822105ba79b65)

Have fun!
fG!