Can someone list, or tell me who the major companies are in SAN FRANCISCO that offer co-location services? I know only about Level3 near Pacbell park. Pls list and give comments. Thanks!

Almost major player you could think of is in the area. Not specifically in San Francisco. But MFNx have DC in San Jose, Peer 1 also does. I can't think of any major carrier which is not in presense in the San Francisco, Palo Alto, or San Jose. If you're looking for San Francisco specially, try Exchange colo, almost everybody is in there. http://e200paul.com for more information.