Camino is free, as are most browsers these days (Ominweb, I'm looking at you), but that doesn't mean you can't chip in to support development. The Camino Project recently announced that they can now take donations. Working with the Mozilla Foundation the Camino Project has setup a way for you to donate money to support the app, and get the added bonus of writing it off on your taxes. Best of all, the Mozilla Foundation will offer a 2 for 1 match until the end of the year, or until the donations reach $10,000, whichever comes first.
If you're a big Camino user be sure to head on over to their donation page and send 'em a few dollars.