I have the need in my application for users to upload many different types of documents and images. Currently I have two ways of doing this; the first is to save to a set of directories organzied by user in a file system, the second is in the data base. Neither of these are really ideal for many reasons that I'm sure you recognize. To resolve this issue, I built a component that extends the ASP.NET file upload control to allow you to save files to the Amazon Simple Storage Servce (S3). I've released the source code and component with an open source license, so you can download this and use in your projects as well. The download as well as documentation can be found at http://downloads.slsys.net/S3FileUpload/Default.aspx.
Enjoy and feedback is appreciated!