CONV. - Convert YouTube video to MP3, GIF or MP4
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
Event Hunt - Startups and Tech Events Curated By Locals
Yout - YouTube to Mp3 Converter
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets