According to their website, "Mashable is the largest independent news source dedicated to covering digital culture, social media and technology. Mashable reports on the importance of digital innovation and how it empowers and inspires people around the world." Besides the insanely cool and relevant articles, I really like their use of "infographics." Instead of traditional black text on white background articles, These infographics sort of take graphs and charts and mash them up with traditional articles. I think it's a great way to get your information across in a simple and quick manner. These days, no one spends more than a few seconds on a webpage, so getting their attention is paramount.
Turntable.fm is like a social media website for streaming and sharing music with your friends. pretty hip.