ExpanDrive

gfxCardStatus by Cody Krieger is a nice utility which lets you know if your new i5/i7 MacBook Pro is running integrated or discrete graphics. Version 1.6 let you manually switch between modes, but any app could still force a switch. As of v1.7 you can force integrated graphics or discrete graphics.

This is a killer feature that should be built into Snow Leopard. It is still a tad buggy – switching tabs in Chrome while Flash video is on occasionally freaks out. Overall it does wonders at keeping an extended battery life while mobile at no noticeable expense unless gaming or watching HD video.