Forum:How do I make a message to everyone in the wiki without going to everyone's talk page and posting it there?

The title says it all.
 * If you are an admin, edit "MediaWiki:Sitenotice". You will also need to increment "MediaWiki:Sitenotice id" every time you change it.  See mw:Manual:Interface/Sitenotice. -- 04:04, May 29, 2010 (UTC)