I've been completely addicted to the Sharkrunners game hosted by The Discovery Channel. It's a promotional/educational tool, aligned with their "Shark Week" sweeps week ratings booster. It uses real shark data to position 6 sharks off the southwest coast of California. You are given a boat (not quite a ship) and a few crew members. You have to plot your course to meet up with the sharks, and decide how to collect data. You get dollars for collecting good research data, which can be used to improve the boat, acquire better gear, or to hire new crew members.
It's quite well done, with a few very minor nits. I'm just about to finish collecting full sets of data on all 6 sharks, and have gathered over $300,000 US in the process. I've been reinvesting every penny back into the research team, and now have an improved boat and almost all the gear I can buy.
It's not a very challenging game, but it's extremely compelling because it forces you to think about the geospatial data as well as trajectories, fuel consumption, state of crew fatigue, and strategies for collecting data to minimize risk. It awards you with various "accomplishments" - like collecting a full set of data for a shark, or increasing the skill level of a crew member. Some awards come with hefty cash prizes, too.
The game is also addictive because of the constant feedback you get. It runs in "real" time - it doesn't pause when you log out. So, you set a series of waypoints for your research vessel to travel, then come back to check in on things. When a shark is in range (detected by sonar) you'll get an email, or SMS message. I guarantee you'll respond to those. Very cool way to keep people coming back in. There are also rewards for responding quickly. Pavlov's dogs are slobbering all over the place.
This is an excellent game, and one that I'd definitely be using if I was teaching biology.