TimeBridge is a free scheduling tool that lets you:

• Share your availability with colleagues in other companies or on different calendars
• Find time that works for everyone — automatically
• Invite anyone; attendees need not register

Extend the Power of Apple iCal

TimeBridge has integrated its innovative scheduling tool with Apple iCal so that users can see their calendar details as they select meeting times to propose to their attendees. Proposed meetings times are held on their calendar and removed once a time is confirmed.

You can even share your availability with colleagues in other companies that use other calendaring systems like Outlook or Google Calendar.