Raise fish with your Opera.

I just found an interesting Widget in Opera Widgets - SimAquarium (Computer Simulated Fish Tank). Unlike ordinary electronic fish pets, you can use money to buy lights, decorations, and new types of fish in this Widget. If you want to earn more money, you just need to wait - you can get one dollar per minute. More interestingly, the fish in the aquarium can reproduce, and when you have enough fish, you can sell them and then buy bigger and prettier ones. However, the most expensive animal in this game is not a fish, but a dolphin. Sometimes the dolphin will leave your aquarium - but don't worry, it will come back.

Additionally, you can take pictures of your aquarium - just click on the camera button.