I have started to use AwesomeNote (or aNote) and I really have to say, it is amazing. It really feels like it brings functionalities that were simply not available in the base Calendar, Note and Email applications.
I have been using it to create a personal diary, and the app makes it easy to insert pictures taken with the camera into a note and associate it with a location (restaurants, shops, …). It would seem like an evident idea to be able to link locations with notes, but sadly the standard apps dont seem to agree.
Now even when creating an Email, I first prepare it in awesomeNote (for things like adding multiple pictures with descriptions, or maps with annotations) before using the Send by Email function which generates an HTML page and then exports it to the iPhones native mail application.
And I still havent said anything about the rest of what it can do. If you dont have it, try it.