I have just got a MacBook Pro and have been using it (+Fusion) to develop on for about a month now. The purpose of this question is similar to Hidden Features of C#; to become
This is not purely .NET related but it is in the vein of the using Spaces item in the question.
Trackpad tips for a MacBook running Leopard (may not be supported in earlier OS X versions):
Set System Preferences, Keyboard & Mouse, Trackpad to use Two Finger Secondary Click. This allows you to use two finger taps instead of the Control + Click combo for the Secondary Click (better know as the context menu to us .NET developers).
Set System Preferences, Keyboard & Mouse, Trackpad to use Two Finger Screen Zoom for magnifying an area in the screen by holding the Control key and scrolling up or down. This is useful for quickly magnifying small fonts or image detail in any Mac application and in Windows running under VMware Fusion. You can pick either the Control, Option or Command keys for zooming by clicking the Options button along with other settings.