Put a human face on your linking: XFN. Originally designed for blogrolls, but useful in any situation where you link to a personal Web site, XFN is a grass-roots social networking tool that anyone can use at any time on any site. I’m using it on my blogroll right now, in fact.
The goal of XFN is, quite simply, to make it possible for links to carry information about the human relationships behind the linking. It lets you designate which links are to the sites of people you’ve met, which are to those who are your friends, which ones represent your sweethearts, and quite a bit more. Best of all, it does all this with just a few simple values that can be added to any link. The great thing, from my point of view, is that it adds a lot of interesting semantic value without being overly complex or difficult to understand. Check it out!