biz-e is a fantastic add-in to Outlook that enables you to easily offer multiple meeting options and invite multiple attendees. It shows you the availability of attendees in one quick view, reserves your tentative times to ensure you dont double book yourself while meeting times are being finalized, eliminates time zone confusion and much more. And, the people you invite do *not* have to have biz-e for you to use biz-e to coordinate with them!

The license of this software is Freeware, you can free download and free use this outlook add-ons software.