Via Lifehacker:
Yahoo!’s launched Site Explorer, a beta search application that displays all the pages from a given web site that exist in Yahoo’s index, as well as all the recorded inbound links to that site.
Aimed at webmasters, Site Explorer offers the page results in a text tab-delimited file for analysis, so that web publishers can determine which pages on their site are missing from the index. Interesting tidbit: Yahoo! Site Explorer lists 10,881 inbound links to Lifehacker whereas Technorati has recorded 2,127. Go ahead and type your favorite site into Site Explorer to give it a whirl.