An update to the Android version of Dropbox is available in the Android Market. One of the new features is the ability to upload any file type, however when I first tested this option on my Nexus One I only saw options for selecting files in Gallery, the Android Music app, doubleTwist, and Sound Recorder, all applications that are on my phone. Dropbox does not have a file explorer, so you need to have a third party file explorer on your phone, like Astro. After I installed Astro it was then available as an option for me to use to browse and select a file.
Additional options are now available when you tap and hold on a file in Dropbox. You can now delete, download, and share files by tapping and holding on a file. Finally, Dropbox has made several file type fixes, which you can read about on the Adroinica web site.