Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
TechEvents.co - Tech and startup events aggregator
Leade.rs - Leaders matches event organizers with speakers in tech.
Facebook Local - Discover places to go and events happening near you
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Conference Shop - 200+ tech conferences to sponsor and exhibit