Pinch to Zoom on Macbook Pro 2007
Actually it can only discern between one narrow touch moving and one wider touch. It's not tracking multiple points - just calculating the area of touch and the single general motion.

Some other questions here might help explain this better:


Are non-unibody MacBook Pros capable of Lion&#39;s 3 and 4 finger multi-touch gestures?
MacBook multi-touch trackpad support
Make Solid-state scrolling trackpad behave like Multi-Touch trackpad


No amount of software will make up for your solid state based trackpad. You might be able to get a Magic Trackpad or use an iOS device to inexpensively upgrade your hardware set and take advantage of multitouch.