My family ships a lot of boxes during the holidays, and we go through a few rolls of packaging tape. Large pistol-grip tape dispensers don't work well on smaller boxes — I have never been able to get the hang of using the serrated blade to cut off the tape.
I was happy to find out about Scotch's Tear-by-Hand packaging tape. I (and more importantly, my wife) can easily tear off strips with our hands. It's easy to get the length you desire, and the tear is perfectly perpendicular. Also, it's easy to find the end of the tape on the roll by running your fingernail along it. This stuff is like magic. I never want to use any other kind of packaging tape. — Mark Frauenfelder