We have just finished our first production version of a free-busy sharing service for Outlook users. You can check it out at FreeBusySharing.com. Using this service, you can share your free/busy calendar data with any Outlook user in the world, and they can share their’s with you. You can then use Outlook’s built-in free/busy time viewer to check for times to meet.
If you work for a company running Exchange, you probably use Outlook’s free/busy viewer every day to schedule meetings. This great tool allows you to easily see when your colleagues are free for a meeting. Unfortunately, without great effort, you cannot use this scheduling tool to see free/busy information for people outside your business. With our service, you can easily solve this problem. All you both need is a supported version of Microsoft® Outlook (i.e., 2002, 2003 or 2007).
Once you have completed the setup, you can easily schedule meetings from within your Outlook meeting scheduler. The free and busy times for each invitee should appear in your planning window and look similiar to this (Outlook 2007):
Check it out!