For example, when I'm done playing a song in Droid, and I want to close the music player so that it doesn't take up CPU, how do I do it? I can only pause a song, and then hit the Home button to go to other applications, leaving the Music Player process running (you can tell by going to Applications->Running Services). In this sense, I just paused my song and went back to the desktop, but not really closing the music player.