Among the core-utils, find is one of the most useful commands. Though I use the basic functions most of the time, find has a wide range of parameters, and it comes in handy not only for finding files, but also for operating a bunch of them at once. Here is a very simple example.

Imagine you have to move many files to a directory, but they all call different so a glob is no use, and manually moving all of them is not an option. A possible approach would be to locate the first of the batch (for example by running ls -lrth). Suppose the first one of the batch is called /tmp/checkpoint (for this example let's assume the files reside at /tmp).