Here's an idea someone might like to try.
Picture a small POP email checker (maybe IMAP), that will look for a specific sender (your mobile maybe) and will execute predefined commands depending on the subject of the email. You could even have it check the body of the mail for extra parameters.
The app would have a list of aliases that correspond to commands.
Play="C:\Program Files\Windows Media Player\wmplayer.exe"
So an email with
with a Body of "myplaylist.wpl"
would run "C:\Program Files\Windows Media Player\wmplayer.exe" "myplaylist.wpl"
Just an example I'm sure some of you could come up with more useful or more geeky examples