Outline+ for iPad is a note taking app that focuses on keeping your notes organizes in outline format. You can create different notebooks for different purposes and organize and drill down inside of those as well. You also get Dropbox, Skydrive, iTunes, and Box syncing support.
Whether you're overly compulsive about organization or you struggle to keep thoughts and notes organized, Outline+ is a great solution. Outside of syncing with all of the popular services, you can also share notebooks with other users and stay in sync with each other. Outline+ also supports embedding images and other types of media which makes it perfect for school or design projects.
The price tag may be hard to swallow for some so there's also a free version available that only supports iTunes syncing. It at the very least makes a good option for trying before you buy. While apps like Evernote let you take free hand notes, they can be somewhat hard to manage. For those that like more structure and the ability to be completely OCD about their notes and how they organize them, Outline+ will give you those options and then some.