There are actually quite a few 411 services out there but not all seem great. I found two I like though:
Residential and business listings available through 1-800-INFOFAST and 1-800-DIAL-411. Search by heading, type of business and partial names of businesses. This service is not so quick, but it is free.
1-800-GOOG-411 searches for businesses only, but it’s quick and easy . . . and by the way, it’s Google.