You can access ShifD through web interface or through browser bookmarklet or using a desktop application on top of Adobe AIR.
While you are on a web page you can just click on browser bookmarklet to save that link to your ShifD account.
Desktop App is also easy to use and similar to web interface. You can also access your ShifD account from your mobile phone, there is an mobile phone optimized web page for the mobile phones.
You can add tags to your notes or links to track or filter them easily. I like it’s simple interface, just nothing but what needed to take notes.