Evernote is one of the best reviewed new technologies of the past few years, and can be used in multiple ways both in and out of the classroom. With everything from Evernote Food to partnering with StudyBlue to pull Evernote notes into flashcards for students. One thing that has been particularly useful is that Evernote can be installed on your desktop, is an available app on Android and iPhone, and syncs across devices.
Pinterest lets you organize and collect things you find on the web-the company calls it a virtual pinboard. You can make pinboards private or share them with others, and you can create boards for classes, topics, or research.
Delicious is a bookmarking service that allows you to curate and discover across many mediums-tweets, blogs, news stories, and organize them into different topics. For me, it helps me keep track of articles I've read without having a long list of bookmarks, and also divides those out into topics I'm interested in. By putting a bookmarklet in your toolbar, it allows you to "add to delicious" and subsequently tag it with keywords you've developed.