If you need an Android app to record tracks and creating voice markers I recommend Osmtracker-android: http://code.google.com/p/osmtracker-android/
As far as I know, first program for Android platform with GPX voice markers (waypoints) support.
(more about this functionality: http://josm.openstreetmap.de/wiki/Help/AudioMapping/SeparateClips )

It works!!! :D