This is just another day in the life of Rebecca, a lifeline telephone crisis supporter at a suicide prevent center in Australia, but for many of us, it reveals a startling glimpse into the darkest side of human capacity.

Tumblr kicks off its first-ever end-of-year retrospective with an epic breakdown of the site's most re-blogged content in 20 different categories, from the usual fares of art/design, tech and music to Internet-favorites like "most viral," and "funny" and the greatest hits on Tumblr Radar.

DJ Earworm brings his sixth annual mashup United States of Pop, wrapping up 25 greatest hits from this year in pop music.

Overheard conversations, now available in real-time.