After nearly 2 years of use, the power adapter for my iBook died this morning. It was working last night, but today, when I plugged it in at work, I got a shock, and noticed that there were bare wires visible. It would no longer supply power to the laptop. When the Apple Store opened this morning, I ran down there and got a new power adapter, which is working just fine now.
I think I also need a new battery, but that can wait a little while longer.