I've always felt that there are really two main problems with searching the web - either you can't find what you're looking for because the content doesn't exist / hasn't been indexed, or you can't find what you're looking for because too much content exists.
The first issue seems to be the one that gets the most focus, but I find the second equally frustrating. Well, Scott Mitchell came up with an idea that touches on both ends of the problem (a twofer, if you will).
He proposes using a gmail account as a knowledge base to subscribe to specialized content such as USENET groups, forums, Yahoo! Groups, etc, and then taking advantage of their mass storage and excellent search capability to perform focused searches on content that is often missed by search engine spiders. Brilliant!