I've seen countless players in the IRC spamming to others to join their server, and it's not really a good way to advertise your server, is it? There needs to be some better form of server advertising in-game. There are players who don't use the forum, so they might get stuck.
This is an idea I had in mind; the host of the server would take a special screenshot of their server while it's running, and somewhere on the server list, there would be an additional section where the screenshot would go, with a random chance of appearing between screenshots taken by other hosts of other servers, and clicking on it would automatically highlight the server's name on the list. Maybe Badspot can create an update for it after v21?
Yes, I know there is an IRC channel used for looking for servers, but most players aren't even aware of its existence. And asking people to join your server on the general discussion channel is rarely ever effective.