We’ve added Box.net’s slick filesharing widget for your WordPress.com sidebar customization pleasure.
You can share very large documents, photos, videos, and music files with your blog readers by uploading files to Box.net and adding them to the Box.net widget in your sidebar. The first gig of storage is free, up to 15 gigs is available for a fee. You can see one of their widgets in action on this page. And here are our instructions for adding the widget to your blog. Enjoy!