Co-Location.com 
Wholesaler of Level(3) colocation and bandwidth services worldwide.
http://colocation.com/Colocation Search & Datacenter Forum
Forum board dedicated to topics regarding colocation and datacenter information.
http://datacentertalk.com
Advanced Colocation Services
Provider of colocation services with facility providers including Hurricane Electric, Level 3 and Equinix in the United States and Europe.
http://advancedcolocation.com
Data Center Map
Data Center Map is a free index of co-location data centers from all over the world.
http://www.datacentermap.com/
Colocation Hosting
A source for information on set up of Internet bandwidth and server hosting services for dedicated and web hosting servers at an Internet data center service provider.
http://colocation-hosting.org
