My favorite feature in A9 is the search history and notes I can store on each page and the best part is that I can access them all from any computer, now that’s power! 

Guess what. Amazon has released their search engine beta verison. It is called a9(which reminds me with Microsoft's new weblog portal channel9.com). Here are the seven reason to use a9.com(according to Amazon.com)

1.Search Inside the Book
2.Adjustable Columns
3.URL Short Cuts
4.Search History
5.Click History
6.Site Info
7.Web Search(provided by Google)

As expected, they also have toolbar. I like the "Search History","Search inside the book"  features. Slashdot article describes like this

"What makes this particularly noteworthy is that A9 is built quite literally on top of Google. In short, Amazon has taken the best of Google, and made it, to my mind, a lot better. Sound familiar? Yup, it's what Google did to Yahoo, Yahoo to Netscape...you get the picture."

[Weblogs @ ASP.NET]