In knitting speak, pearling is just a fancy schmancy term for creating ribs in your crochet project. Ribs help to create a regular pattern and add visual interest to caps (as in this tutorial), scarves, Afgans, and just about any crochet craft.
In this video, Mikey shows you how to pearl using a technique of pearling after your work is completed. He is showing you on a hat brim how to do this... but this can be done on afghans and much more as well. Listen carefully as this method isn't for everthing. This only works when you want to pearl completely down one peg line for your entire project.