What do you use? Yellow Pages or the Web?
I still use the Yellow pages for local listings since Google still doesn't deliver all the information I need, and services like Citysearch are lacking in thoroughness when it comes to restaurants. According to this survey by the Kelsey Group and ConStat as reported in this New York Times story (registration required):
The online survey found that 67 percent of small businesses that have been in operation for over 20 years still rely on Yellow Pages. The figure drops to 52 percent for companies less than 10 years old, which are also more likely to spend money on online directories and services that promise higher placement in Web searches.