I spent quite a while watching this spider sprint across short stretches of water. I was very impressed, and asked on bugguide what sort it was.
A wolf spider.
Really? Ok, yeah, it does look a little bit like the one I saw earlier, a lot like it in fact, but I didn't know that wolf spiders could walk on water. I expressed my surprise.
Oh, came the casual reply. "Just about any spider can run over water."
And I never knew. It's amazing the amount of things one can go through life without noticing.