Way at the southern tip of Manhattan Island in New York City is the riverfront neighborhood of Battery Park City. Battery Park City is served by a tiny, hyperlocal newspaper called The Battery Park City Broadsheet - an extra large, four-page fold out that looks like this. (pdf)
There isn't a lot of space on those pages, but every edition includes a "Riverwatch" photo of a ship on the Hudson River or in New York Harbor, as well as the "Arrivals & Departures" schedule (scroll down to the top of page 4 of the pdf above) for the cruise ships that dock up in midtown. I don't know if you've ever seen a cruise ship roll by but it's impressive enough that you really would want to know when the next one was coming so you could plan to see it again.
Anyway, before I digress too far, being fluent in river traffic is a cool thing and the fact that someone on what I presume is a small staff has taken it upon themselves to inform the members of their community what's passing by is also a cool thing.
The map above is a real time depiction of marine traffic around the world. The squares are docked. The pointy ones are moving. When you click them to get details and often even a photo. That's the mouth of the Hudson, above, but the site is hosted by the University of Aegean, Greece, and if you wanna see some boat activity, scroll over their neck of the Mediterranean. It's madness!
The project is open and community-based, which means if you live near the water, you can get the software and some equipment and contribute to the data. The data comes from the the ships AIS (Automatic Identification System) transponders. According to the FAQ, AIS was initially meant to keep ships from crashing into each other. The signal carries identification information as well as position and movement and reaches 10-15 miles. If you want to participate, you hook up an antenna to receive the signal and the software does the rest.
As soon as I read about the community aspect I immediately thought of the Broadsheet guy taking pictures of passing ships out his apartment window. I bet he or she would be into this. So I googled up the the Broadsheet's website to see if they have a tip line or something for sharing. Wouldn't you know, right there next to the masthead, that thumbnail picture of a cruise ship is linked to MarineTraffic.com.