The Macbook trackpad has by far the best horizontal scrolling of any pointing device. I could not live without it. (If anyone knows a better solution please tell me. I'm always looking for new options.)
It's great for spreadsheets. I even use the Macbook trackpad for 3D CAD. I used to use a spaceball and mouse, but the trackpad plus modifier keys is more convenient because it keeps the hands to the keyboard.