DropDAV is a simple way to allow access to your Dropbox files via WebDAV. Mostly I made it so I could allow the new iPad Pages/Numbers/Keynote apps to read/write files to my Dropbox. But you can use it too!
You'll just need to "link" your Dropbox account to this service, then choose a password.
NOTE: You can only upload/download files of up to 1MB in size through WebDAV. This is due to App Engine limitations.