The Five Things That Yahoo! Search Can Do But Not Google | India Inc. - [Stumbles via StumbleUpon]

I found the last one very interesting:

5. linkdomain - An undocumented Yahoo Web search operator.
A quick question - Can you find the number of articles on Wikipedia website that link to CNN.com ? It’s almost impossible to get this data from Google but you can do so quite easily in Yahoo! with the incredibly useful linkdomain operator. The answer is:
linkdomain:cnn.com site:wikipedia.org