I love polka dots and have been collecting them for years. I think they look great for pinwheels and rail fences. I also saw a log cabin done with them that was really fun.

Nine-patches and four-patches in assorted sizes that fit together. (Mine is still at the blocks stage, so no photo.)
12", 6",4",3" blocks all work well together. You could even have an 18" or 24" if you have jumbo dots. (I made an effort to mix up the color combinations, avoiding any two blocks being the same pair of fabrics in the same positions.)

I guess polka dots are all the rage now! As was already mentioned...there is a polka dot swap that was just announced!