Turn Up the Volume with RemoteVol
If you like listening to music on your Google Nexus One, and you use the default wired headset, take a look at RemoteVol, a little app designed by XDA forum member t0ol.
RemoteVol lets you control the music volume with the default wired headset. A long press on the NEXT button increases the volume step by step and conversely a long press on the PREV button lowers the volume.
Made for the default stock Android music player, the app has been tested as working on (but not limited to) FroYo and the Google Nexus One.
To download the apk and provide some feedback, check out the application thread.