I've noticed that on some people's "location" information next to their postings (where it says your user name and avatar etc), it actually hyperlinks to the map and tells you how far you are away from them. How do you do that?

You are linked fine - the link doesn't show up for you as it would only tell you where you are

I can confirm it shows up for everyone else

Ah yes, so it does, I can see it if I log out.... thanks!