Event calendar plugin that allows you to add a nice-looking scheduler/planner with drag-n-drop interface, recurring events, Google Map integration.
After plugin activation, you will have a new page in your blog, with calendar on it. You can configure it through Plugins menu.
To have the list of upcoming events on the sidebar, you can add the next line into sidebar's template
<?php if (function_exists('scheduler_sidebar')) echo scheduler_sidebar(); ?>
If you are using a widget-capable theme, "Upcoming Events" widget can be used for the same.
Export to iCal format
To add such possibility, just add the next link somewhere on the page ( inside post, or inside sidebar's template )
<a href='./wp-content/plugins/event-calendar-scheduler/ical.php'>Export events</a>
If you need to export only upcoming events, the link will look as
<a href='./wp-content/plugins/event-calendar-scheduler/ical.php?oncoming'>Export upcoming events</a>