Snip.it (Acquired by Yahoo)

Snip.it lets you keep an annotated, shareable library of the best content you find online. You can snip anything on the web, add your opinion, then organize it into collections themed around the topics you want to catalog. Great pieces of journalism, funny videos or memes, articles for a research project — your Snip.it library lets you save the content you care about and express yourself through your interests. What’s more, you can discover new content by subscribing to other Snippers’ collections. All the snips from collections you’re subscribed to will show up in your My Subscriptions tab. You can also browse snips from collections we’ve featured on the Featured page, or search any topic to see what people are snipping around it.