The amazing solution, see this article: http://www.fivecentnickel.com/2007/11/18/fixing-a-macbook-pro-trackpad-button-that-sticks/
I run 2 macbook pro laptops from 2007 and 2008. They are wonderful machines, but they suffer from a 'crunch' type click on the trackpad.
I have been looking for a solution for this for some time, and have done the 'origami' method, tried wedging things behind the battery - all of which seem to help, but actually do not.
The result, a NEW feeling trackpad. I am so happy... I could cry!
This is totally off-topic, but… My main computer (work and home — it goes everywhere with me) is a MacBook Pro. Over the past few weeks, I’ve noticed that the trackpad button has been sticking, like it has something stuck underneath it. Cleaning crap out of the keyboard is easy enough – just run the Shop-Vac over it and everything gets sucked out. But the trackpad button? That’s an entirely different story.
The problem in this case appears to be that the opening between the trackpad and the button (see crappy cell phone picture, below) is big enough for small, foreign objects to enter.

The solution? It’s surprisingly simple. Just insert the corner of a piece of paper into that gap and slide it back and forth to dislodge whatever’s causing the problems (again, see the crappy cell phone pic, below).

That’s it. Assuming that the foreign object is “dis-lodgeable,” your problems should be solved and your trackpad button should work like new.
