TechEvents.co - Tech and startup events aggregator
Eventcal - Facebook events filtered for your calendar
Facebook Local - Discover places to go and events happening near you
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.