The fountain I have plugs into the same return that my Polaris does. It has a center spout and 4 bubble-looking floats in a wagon-wheel sort of design. I think DH picked it up at Leslie's for around $100.

Most fountains are decorative, but this one serves two purposes--it does do some water cooling during the hottest part of the summer, and if you need to drop your alk or raise your pH, aeration is the way to do it, and it makes a fabulous aerator!