I've been making videos lately, as I've mentioned. So among other things I've needed to know the total length of a bunch of .wmv files. Now sure, if you have a spreadsheet you can teach it to add up times. But the ironic thing is, I was asking the file system for the length (in minutes) of each video, then adding them up, when I could have just asked the file system for the total length!
Well that's fun! Notice it also adds up the total file size. I find these little savings really add up to keeping me focused on what I'm really trying to achieve (write a tutorial) instead of getting caught up in minutiae.