Need a good Public Events Calendar plugin for multi-author blog

I manage a website of published authors and I’d like to find some kind of plugin that will show public appearances (book signings, conference speaking engagements, etc) that our authors will have so that visitors can see at a glance where we’ll be around the world. Ideally we could create an event and attach the authors (who are WP users) to it that will be at that event. We also use BuddyPress if that helps, but it doesn’t have to be integrated. Just need to be able to attach the authors (who are Users in the WP system) to the event. Any ideas? Free is great, but we’re willing to pay too…