We tried doing something similar at XMarks (a bookmark sync service) when I worked there. We figured bookmarks were a good source for mining quality websites and hired some very bright people with a search background to build it. For some searches, it gives pretty good results. Here's the one it gives for VPN providers:
http://www.xmarks.com/topic/vpn_providers
It was an uphill battle for us, which ultimately never worked out. Early on, we did a usability study with users to see how they use search engines and the people we interviewed tended to think that google was more of an expert than themselves and if they were having trouble finding things, it was more their problem than google's.
We ended up trying to take our data and tried decorating it directly on the google search results page to start getting usage, but it was really hard to get any traction and build any momentum. For most searches, Google is good enough and only a small number of our current users started using our website for search/discovery.
We ended up spending a significant amount of time decorating the ads within search results and after a considerable amount of logging and number crunching, found that decorating those ads not only increased the clickthrough rate of ads we decorated, but also increased the overall ad clickthrough rate. That's a huge win for a search engine and worth a lot of money, but ultimately google just did it themselves, and for other search vendors that had ads on their pages, they were basically handcuffed to google's contract which wouldn't allow them to use our technology.
TL;DR - Competing with Google is hard.