We have created a custom version of our product for HN which, like several other YC-funded companies who's products PG thought relevant, are linked to in the HN footer. Perhaps the fact our icon says 'HNSearch' is a problem - maybe we need to change this to 'HNSidebar'?
To clarify - we make browser addons that allow you to personalize the right-hand side of the Google search results page with sources that you value. When you search on Google (and others) we open up a sidebar on the right of the page where you can see more results from sources that you can select, some of which Google cannot, or does not, show you - e.g. searches across your Facebook or LinkedIn profiles, or Gmail, or your own Delicious bookmarks.
Hacker News is one of the sources that you can select in our sidebar and we've created a specific version of our addon that shows results from HN, by default, in a larger widget than normal. That's powered by Bing site search and if you click on the title of the widget, it'll take you to searchyc to try your search there. Some other sources are also powered by Bing site search where we think that's the best way of showing the results. For many other sources we use their own search APIs, like Digg or OneRiot which put a big emphasis on recency and explicit user inputs.
Our product lets you tell Google: "A lot of the time I want to see New York Times and Hacker News search results when I search, so show me what they've got on the right-hand side."
I hope that helps and we'd love comments on our actual product and how we can make it work for you.
