I used to use these all the time when my daughter, Mims, was a baby/toddler. In my opinion, there is nothing as gross as trying to figure out where to put a dirty bib. I know, some of you will say that cloth diapers are worse, and I will not disagree with you. What I will say, though, is that if you make the wonderful decision to use cloth diapers, you have a contingency plan in place on how you're going to carry the soiled item home with you if you change your little one in public. When Mims was tiny I never was organized enough to plan that far ahead.
These little miracles saved my sanity. The bib clips are super simple to use. All you have to do is attach the clip to a handy bib-like stand-in and you're good to go! Best part is, if that item is something disposable, like a napkin or paper towel, you can just throw it away after you're done, and you don't have to bring something covered in mushy peas home to wash.
You can use other bib-like items with it too. I used to use tea towels, cloth diapers, and washcloths (you know, the kind you can pick up a dozen at Target for $3). Those were also more convenient than a regular bib, since you can pretty much cover a 10 month-old with a tea towel.