There seems to a be a real need for a good calendar of content management events. To help fill the void, I started adding events to Upcoming.org and tagging them with "cm+conference." I chose Upcoming because they are owned by Yahoo! (so I am pretty sure they will hang around) and they use microformats. You can see them here.
I also burned the feed on FeedBurner. This allows you to do cool things like the little Ajax block on my resources page (see "Upcoming Content Management Events"). If you want to add the same section to your site, all you need to do is copy the following code onto a page.
<noscript><p> Subscribe to RSS headline updates from: <a href="http://feeds.feedburner.com/UpcomingorgUpcomingPublicEventsTaggedWithcmconference"></a><br/>Powered by FeedBurner</p> </noscript></p>
So, if you have a conference that you want to promote, add it to Upcoming.org and tag it with cm+conference. It will show up on my site and any other site that wants to display these CM Events.