Remember SmarterChild? That AIM bot that would answer all/most of your questions and get huffy and stop talking to you when you inevitably started swearing at it? Unfortunately SmarterChild is still dead and gone, but it's got a Twitter descendant: @DearAssistant.
DearAssistant is a simple Twitter bot designed by Amit Agarwal for a single function: answering your queries using Wolfram Alpha. On his blog, Agarwal describes his little project as "a mini version of Siri," which is apt considering they both use the same data source. Except with DearAssistant, no one has to say anything out loud. It can be a little slow sometimes, but it works remarkably well.
The bot's code is all open source, so if you're into tinkering, you can use it as a jumping-off point to make a little robot Twitter-wizard of your own, or you can just harass it and make it spout answers to the trivia questions you fling at it.
It's not the most robust question and answer system out there, certainly not as good as Google or actual Wolfram Alpha, but it's definitely on the "actually useful" end of the Twitter-bot spectrum. A hell of a lot better than the legions of god-awful parody accounts. And that's something worth celebrating. [Digital Inspiration via The Next Web]