Search Engine Blog mentions a Microsoft project, MSRA SRC Toolbar which you can install to provide clustered search results. The tool is very much in “beta” as far as it’s functionality. You can only search MSN, MSN Beta or MSN News. Results are clustered in the left window and web pages in the right. Clustered results can be exanded to sub categories.
In comparison, Clusty from Vivisimo is far more refined. There was a good article on Clusty recently in BusinessWeek Online, “Building a Smarter Search Engine” If you want to get clustered search results from MSN, the MSRA SRC Toolbar is an interesting find.