I've found a new mindless hobby - playing Eliza with Encarta.
The Windows Live Messenger team were first to put me on to the fun new service offered by Encarta, whereby you can add email@example.com to your MSN IM list and ask it free-text questions such as "Where is the capital of Bolivia?" or "Who is the president of the USA?" It's pretty good at parsing the meaning of your questions and giving you an answer out of the encyclopaedia corpus. For geographic questions, like "Where is Reykjavik?", it gives you a textual description of its location and displays a MapPoint map alongside the chat window. It can even answer mathematical questions (for example: "Solve 6x^2 + 3x = 30").
But the programmers obviously had a little fun and added answers to other, perhaps less encyclopaedic, questions. Leah has a couple on her blog which are quite good; it's also worth trying these:
What gems can you find?