Some of the handiest features that I have in my custom VB App, which you might want to include are:
- ability to browse through your hard drive (*.mp3 of course) with the keypad
- when a song is highlighted you can either play it right away or enqueue it
- auto shutdown - automatically shutdown after the current song is finished.
- control the EQ (if using winamp)
- last song recall - like last channel recall on a TV remote
The browsing is the single most handy feature in my experience. I wasn't able to find a program that would do it reliably so I had to write my own.
Other features which I will be implementing later, would be
to be able to play songs which haven't been listened to in a while, and songs which I have just downloaded (based on the filedate) - similar to those Portable MP3 players.