A friend of mine has been ranting and raving to me recently about how he can access his computer's movies, music and more via his cell phone through a new Winamp Remote service.  Upon investigation, I learned that Winamp's service is powered by Orb, a company that I became familiar with a few years ago.  Orb's technology has come a long way since then and does essentially what my friend mentioned - allows you to access music, videos, photos and other content from your computer's HDD via any Web browser or Web-enabled PDA or cell phone granted the source computer is on and the Orb program is running.
What I believe makes this application even more powerful is the ability to then share selected content with others.  For example, I now have access to my friend's shared DVD and music collection and while that may not make the business world go round, sharing corporate photos and documents with my colleagues in Europe does.  Take a look at Winamp Remote or Orb to learn more.