Soonr's free service and accompanying App Store download allows users to store up to 500MB of files, which they can access on the go, from the iPhone or a standard Web browser.
New users create their account on their iPhone and then download a desktop application (available for PC or Mac) which handles the synchronization of files. In the same form of other desktop-syncing applications, the user only has to choose the directories that they want to keep updated, and any changes made will be automatically uploaded. All of these files are easily accessible from the iPhone app.
Not only does Soonr allow you to have very quick access to your documents from the iPhone, but it also allows you to share the documents with other users. These users can view and comment on the file.
Unfortunately, Soonr does not currently enable users to edit these documents. But its application does include a wireless-printing feature, enabling users to send documents to networked printers when on Wi-Fi.
My only real gripe with the iPhone app is the lack of full-screen support within the document viewer. The iPhone's document viewer does a better job of actually displaying documents than Soonr's.
Soonr is a great solution for iPhone users looking to have constantly synchronized documents on the go. Soonr is very easy to use, fully featured and, best of all, free.