I’m pretty sure I’ve mentioned Gliffy, a Web service that lets you draw and diagram anything you can think of—think Visio in your Web browser. And it works in Opera and Firefox.

I’ve done up my home network map in Gliffy:

The “proposed” line at the bottom signifies adding another segment for a TV in the bedroom, if we decide to do that. The existing TV is in the guest room.

Note added 2008-02-18: An updated version of this post is here.