Everyone knows that you can track airlines online -- there are several websites for that. But did you know you can also track ships? Here's a website that lets you key in any port (feel free to do it by city name if your city has one) and bring up a map of all the live ship traffic.
Ship tracker by MarineTraffic.com
You can click on each ship icon to bring up specific information about that ship or maritime craft. It's a nice way to kill a few minutes if you're a maritime aficionado.
Unfortunately I've yet to find one that does as equally a thorough job for trains -- though Amtrak will allow you to track its own trains specific routes in a similar way (I note that it's unclear how to actually use the Amtrak web service, but this private version of the same seems to actually work).