1. Google
2. Bing
3. Yahoo!
4. Yelp
5. Merchant Circle
6. LinkedIn
7. YellowPages.com
9. Whitepages
10. Supermedia
11. Yellowbook
12. CitySearch
13. Mapquest
14. Biznik
15.http://w3-directory.com
15. Local.com
16. Foursquare
17. ThinkLocal
18. CitySlick
19. USYellowPages
20. SuperPages
21. Outside.in
22. Dex
23. BizJournals.com
24. TeleAtlas
25. JustClickLocal
26. Discover our Town
27. Metrobot
28. EZ Local
29. twibs
30. LocalEze
31. Kudzu
32. CityVoter
33. Manta
34. Zipweb
35. MatchPoint
36. UsCity.net
37. Local Site Submit
38. InfoUSA
39. Axciom
40. Infignos
41. Yellow Assistance
42. Get Fave
42. My Huckleberry
43. GenieKnows
44. MojoPages
45. Brownbook
46. Magic Yellow
47. seo support
47. CitySquares
48. TeleAtlas
49. Navteq GPS
50. Judy's Book