A number of months ago, Amazon introduced its new A9 search engine, dubbed as a potential “Google killer.” After a few days the buzz about A9 went away, and we didn’t really hear about it any more. Until yesterday, that is. A9 has unveiled a new version of A9, and I have to admit it’s pretty intriguing. The home page has a History button that allows you to access and organize all of your past searches. When you perform a search, the results page allows you to see results in various categories — the basic Web, books, images, movies, and reference (powered by GuruNet, if you have a subscription). In addition to the History button, you can also store your bookmarks here, as well as keep a diary about the sites you visit.

Many of the features work only if you download the A9 toolbar, which of course only works with Internet Explorer. But the other features here make this a pretty cool search tool.