This A9.com > OpenSearch sounds like — though I’ll admit I haven’t fully studied it — a nifty way to syndicate and aggregate search results of a website/blog:

Many sites today return search results as a tightly integrated part of the website itself. Unfortunately, those search results can’t be easily reused or made available elsewhere, as they are usually wrapped in HTML and don’t follow any one convention. OpenSearch offers an alternative: an open format that will enable those search results to be displayed anywhere, anytime. Rather than introduce yet another proprietary or closed protocol, OpenSearch is a straightforward and backward-compatible extension of RSS 2.0, the widely adopted XML-based format for content syndication.

Jeff Barr explains how he made Syndic8 OpenSearch-friendly.

Developer specs here:
OpenSearch RSS - docs
OpenSearch Description - docs
OpenSearch Query Specification

Amazon has a history of liking patents on stuff, so I hope the word “open” is followed in this case or it could become convoluted, but I do like the idea of making a search results column for MakeYouGoHmm and being able to integrate it with A9.