This is nothing compared with what I've seen elsewhere but yes, I've got algae growing in a pot. At first I wan't sure what it was but green and somewhat slimy balls growing on stuff didn't take long to figure out.
This is due in part to the new potting material I'm using, easily grown on by the stuff, and the amount of rain we've been getting. As noted in a recent post there's plenty of that going on. I have been watering this pot a bit though between showers but the pot drains pretty good still. Lots of holes in the bottom drilled out by me. Not instantaneous but enough that you can tell it's draining within a few minutes.
This amount of algae fortunately isn't a problem. It's barely even noticeable unless you are looking at the plants and even then I mistook it for fertilizer balls. You know, the kind you usually find in potting soil in the first place. If nothing else I'm sure the plants aren't drying out.