A friend of mine just returned from a trip to Uganda, which she found delightful. The equator goes through Uganda. When you visit the equator (yes, they have a nice little monument), you will meet a man who has a large funnel contraption with "Did U Know" painted on it. For a small fee, he will show you that north of the equator — even one yard north of the equator — water spins counterclockwise as it goes down the funnel drain.
He illustrates this by putting a small flower in the middle of the drain-spiral, which spins counterclockwise in the Northern Hemisphere.
One yard south of the equator, in the Southern Hemisphere, the water drains clockwise, and the flower spins accordingly.
On the equator itself, the water drains out of the funnel without spiraling at all, so the flower does not spin.
The Straight Dope claims this is all a crock, but my friend had videos that showed all this really happening, and she reported no tricks or irregularities. I watched the videos and, in fact, saw water draining out of a large funnel without spinning.
Unfortunately, those earth-shattering videos are still on her computer. But here’s a video of a tour guide imitating a tropical bird, which is charming, and possesses at least some scientific relevance: