Google's advanced search options are useful, but they could include ways to define more restrictions for search results. Maybe you want to find pages that mostly contain text, web pages that reference videos or include tables. Fortunately, some these features are available at Yahoo, where you can use the feature: operator.
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
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.
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.
More Yahoo Search tips