I really like using Onenote with notebook saved on skydrive, I have been able to have the native app on my windows machines and the webapp when I am on the go.

I really like using Onenote with notebook saved on skydrive, I have been able to have the native app on my windows machines and the webapp when I am on the go. Also, there is a really good looking WP7 app now (though I have used it yet)