I’ve been using a few tools that I’ve found to be very helpful. Diigo, Zotero and Evernote. All of them have had recent version upgrades which improved each application.
Diigo is a web book marking application similar to Digg or Delicious but with a big difference. Diigo allows you to highlight and annotate web pages. It also saves that annotation so that every time you visit the site you see the notes from your previous visit. Give Diigo a try. Tool-bars are available for FireFox and Chrome.
Zotero is a Firefox add-on application that allows you to create bibliographical lists of books, newspaper articles, magazine articles, music, etc. Zotero makes this very easy. For example, if you found a book on Amazon that you may want to purchase, Zotero makes it easy to create a bibliographical reference of the book with a single button click.
Evernote is a popular note taking and web clipping application. I use Evernote everyday to clip articles off the web for later reference. What’s really cool about evernote is that it indexes everything that you clip. Even the writing on a sign in a picture placed in Evernote is indexed.
In addition to the web version there are iPhone, Blackberry, Palm Pre, Windows Mobile, Windows and Mac versions of the software. All versions sync with the website. Imagine taking a photo of a menu you like and have Evernote index the entire menu contents. I’ve been using all three of these programs for over a year and have found them to be very useful.
Full Disclosure: I am not affiliated with any of these companies nor have I received any gifts or payment of any kind from Diigo, Evernote or Zotero.