If you own and travel with a notebook computer, the Logitech MouseMan Traveler is the way to go. It’s small, but not too small. It works with all of my machines and all of the operating systems I use. It’s optical, so it works well on any non-reflective surface. Finally, it comes with it’s own little carry case to prevent it from getting crushed in my bag full of junk, and to keep the cord nice and neat. No one paid me to say that.