I assume it was a podcast, but I do not recall which one.
Wherever it was, I listened to a discussion wondering why people use Apple's Magic trackpad. The talkers had heard of people prefering trackpads to a mouse and could not see why. There was even talk of people claiming to be faster and more precise with the trackpad than with a mouse. This last statement seems as strange to me as it did to the discussers. I am definitely not speedier or in some other way better when using a trackpad, but I still do use one for almost all my computer pointing needs. When I got an opportunity to upgrade my pointing device at work I jumped at the chance to get a Magic trackpad.
Here are the three main reasons I enjoy it:
I mainly use laptops. Having everything work the exact same way when I get to work and connect external devices is just plain nice.
With a trackpad I just put my arm in one place and let my fingers do all the work. Pretty much like a keyboard, come to think of it. Less arm movement feels good, I just have to put the trackpad in a good position and leave it there. This could well be psychological to a large degree, perhaps combined with wearing on different muscles than previous years of mouse usage.
Also yes, I am one of those people who sometimes place the trackpad in front of the keyboard some kind of heathen imitation of the laptop setup. Not often, but it does happen.
This is the big one. I have not been impressed by the Magic mouse, and I feel slightly constrained when I do not have access to all the nice swipes, pinches and multi-finger taps of the trackpad. This was what made me even consider the Magic trackpad for my work computer in the first place. Paired with the above-mentioned consistency, I have a hard time seeing how a mouse would be able to lure me away.
Well, unless I suddenly started playing games again. There I am right with the podcasters, I just can not see myself doing well - or even being able to put up - with a trackpad when serious speed and precision is called for.