While Google works very well most of the time, I've found myself using Jason Calacanis' Mahalo.com more and more for certain types of searches lately. In case you're not familiar with Mahalo, it's a human-powered search engine, meaning that the results are compiled by real humans instead of an algorithm. While this limits the number of search terms they can cover, I've found that they have good real-time coverage of every popular news story as well as other general interest topics, and it's really nice to get the information you're after right away (no ads, no keywords buried in a mountain of text). Between Google, Wikipedia and Mahalo, it rarely takes me longer than 90 seconds to find any information I need.
While "human-powered search" is the official tag line, it also feels similar to a few other websites, like Wikipedia or Digg (but without the geek-dominated extreme left wing bias). They also just launched Mahalo Answers, which is quite a bit like Yahoo Answers. I wont judge it yet, as it's only a few days old, but the concept seems to blend quite well with some of Mahalos other strengths (recipes and other DIY tips come to mind). If you've never used Mahalo, try it out.