2021 note: this is not necessary for Blender 2.8+.

Blender has a reputation for being difficult to navigate, but you can get around just fine with Mac trackpad gestures—you just need to set things up properly:

Step 1.
Go to File / User Preferences.

Step 2.
Go to the Input tab.

Step 3.
Make sure the Presets drop-down menu is set to Blender. (An option for Maya controls was a nice idea…but it’s Maya’s older control scheme that requires a middle mouse button. So it’s not going to help us.)

Step 4.
Check Emulate 3 Button Mouse.

Step 5.
Choose Save As Default.

Step 6.
You should now be able to navigate using your trackpad:

Pan: Two-finger scroll
Rotate: Alt + two-finger scroll
Zoom: Two-finger pinch

Step 7.
If, like me, you don’t care for the default Blender keyboard shortcuts, follow these instructions.