Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Event Hunt - Startups and Tech Events Curated By Locals
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.