iraq gdp feature:table - web pages that contain tables, unfortunately including layout tables
la traviata feature:audio - web pages that link to audio files (e.g.: MP3s)
michel gondry ads feature:video - web pages that link to video files (e.g.: QuickTime videos)
AJAX feature:acrobat - search results that link to PDF files
beatles feature:activex - search results that contain the object tag (e.g.: embedded YouTube videos or any other Flash object)
feature:activex site:googlesystem.blogspot.com - all the pages from this blog that include videos
You can also use the operator to remove some classes of web pages. If you want to filter web pages that use JavaScript, add -feature:script:
java -feature:script - old tutorials for Java
lagrange interpolation demo -feature:applet - interpolation demos that don't include Java applets
To find web pages that link to files with a certain extension, use the linkextension: operator. For example, linkextension:ogg bach finds web pages about Bach that link to .ogg audio files.
Yahoo has another interesting operator (depth:) that lets you define the maximum number of subdirectories from your search results' URLs. For example, a search for google tips depth:1 will include www.google.com/help/features.html because it has a single directory, but not www.techcrunch.com/2007/01/04/google-tips-pulled, which has three directories. This could be useful to find web pages that are important relatively to the structure of a web site.
The operator has a special value that lets you search only homepages: -1, as you can see in this query: flickr depth:-1.
Find the sites related to Flickr that don't have a link from yahoo.com
I don't know if Yahoo's search engine is better than Google, but Yahoo inherited a lot of interesting features from AltaVista and Inktomi, two leading search engines in the '90s.
Related:
More Yahoo Search tips