I'm using Evernote for two weeks now and wow! I'm really enjoying it and my everyday web life is very easy and light. Although I don't know yet every bit of it's functions but it really is making my day a lot more easy. Now you can actually use it in posting on your Twitter and Facebook or even send emails. As for me, I'm using it as a notepad or as a reminder of what I need to do on the net each day.
And if you're using Chrome, it has a new right click option for quick clipping. See here. Well I'm still working on it on my cellphone so I can still take down notes even when I'm out.