I have been using Evernote and Skitch on my iPad for a quite while. I must say that the new Skitch for iPhone is one of the must have free iPhone apps which I have been anticipating for its release. Now, I can actually do my annotation on my iPhone and bring across over to my Evernote account more conveniently.
Must Have Free iPhone Apps | Walkthrough of Skitch for iPhone and iPod Touch
Must Have Free iPhone Apps | Skitch for iPad