How to actually do this project should be pretty obvious just from looking at it, as it's Instructables user harari's idea that's particularly clever and not the assembly. Basically, you just cut off an RJ-45 cable and attach it to your key ring, then mount a few ports to your wall. Plug the severed cable into the port and your keys will hang from it securely. Very cool.
RJ-45 Key Chain and Rack [Instructables]