In this blog post, David Anson is sharing information and code for his BlobStore project.
BlobStore was a fun project to work on and it gave me some nice exposure to Silverlight's networking stack (which I don't normally get a chance to use). There are some rough edges I didn't get around to smoothing over, but on the whole I think BlobStore turned out pretty well: it's small and quick to download, easy to use, it simplifies something I do every day, and it was a great learning experience!
Aside: You can even use BlobStore to publish Silverlight applications (just upload the XAP and HTML file), so it's got that recursive thing going for it, too..