Check out these cool EcoSphere Pods from Greenfeet.com. These are mini-ecosystems that are enclosed in glass. They are easy to care for and make great gifts/educational tools for kids. The spheres contain algae, filtered seawater, and tiny red shrimp. The sphere contains all it needs to sustain itself, making it a kind of low-maintenance aquarium/terrarium. Wow! This is way cooler than the sea monkeys I had as a kid!
