You can compile the latest builds from Banshee if you’d like, but for those of you on older non-bleeding edge machines here is the .is_audio_player needed for HAL. Save on the root of your N900 device. This will place the files in the correct locations:
playback_mime_types=video/mp4-generic, video/quicktime, video/mp4, video/mpeg4, video/3gp, video/3gpp2, application/sdp, audio/3gpp, audio/3ga, audio/3gpp2, audio/amr, audio/x-amr, audio/mpa, audio/mp3, audio/x-mp3, audio/x-mpg, audio/mpeg, audio/mpeg3, audio/mpg3, audio/mpg, audio/mp4, audio/m4a, audio/aac, audio/x-aac, audio/mp4a-latm, audio/wav
playlist_formats=audio/x-scpls, audio/mpegurl, audio/x-mpegurl
audio_folders=.sounds/, .videos/, Music/
video_folders=.videos/, Video/
icon_names=phone-nokia-n900
folder_depth=2
coverartfilename=cover.jpg
coverartfiletype=jpeg
coverartsize=200
