The file manager is simple and contains just the basic operations that you need: upload, download, and delete a file. You can also make your data public in order to share it with others.
There is also a note manager, which contains a list of notes and an editor to add new notes, or modify existing ones.
The contact manager goes along those same lines, although it has some more specific controls, including alphabetic indexing, a change history, and a tool to mix contacts.
Ubuntu One wants to become one of the more comprehensive online storage services, and at the moment, it looks like it's on the right track.
Free to store up to 2GB, after which you can pay for more space.