A while back I created a toy IRC bot that answers questions like this just by searching reddit and taking the top comment. It works surprisingly well for questions that are likely to have been asked before. And when it does work, the result is much better than a dry wikipedia excerpt. I then added some simple machine learning to filter search results for the most relevant threads which improved it quite a bit.
That might actually make a new kind of search engine. You should put it on the web?
As I said, it only works for questions that are likely to have been posted on reddit before. Not a general search engine.