It's currently rather limited in functionality:

Usage: mprisshell.sh [command]
Commands:
  play                          Start playing the current track
  pause                         Pause the current track
  playpause                     If a track is playing, pause it; otherwise, play the current track
  next                          Skip to the next track
  previous                      Skip to the previous track
  incVolume [percentage]        Increase the volume by 10%, or the given percentage
  decVolume [percentage]        Decrease the volume by 10%, or the given percentage

It sends the above commands to the first MPRIS-capable player found; this includes the latest git head of YANIHP, Amarok 2, Audacious, and others. It's meant for normal users, not developers, for example as a program to bind to media keys.

Just add the chinook extra's repository, then as root, apt-get install gstreamer0.10-plugins-ivorbis (integer-only decoder). This package works fine on diablo.

It's also useful for various games installers.

As for what I did there:

• Drank lots of Belgian Beer :)
• Learned about new stuff in Qt, KDE, and Linux graphical stuff in general - in particular, Zack Rusin's talk on Gallium3D seems very promising
• Added MPRIS support to YANIHP - so it now support the same D-Bus interface as Amarok, VLC, Xmms2, and others
• Added a tray icon to YANIHP
• Received a free N810 from Nokia...

...which led to:

:D

Surprisingly few changes were needed:

• Added a compile-time option to make it so that left-clicking on the tray icon pops up the context menu, instead of hiding/showing YANIHP - I'll later make this apply to all context menus, where appropriate
• Added a compile-time option to hardcode data and music paths - otherwise YANIHP uses QDesktopServices::storageLocation - which seems to think that /usr/share/mime/data/ is a perfectly suitable location to store non-root user data on the N810...

Here's how to get it running:

• Install taglib (1.5), libqtcore4, libqt4-sql-sqlite, libqt4-phonon on the device, and the corresponding -dev packages in scratchbox
• Also install cmake in scratchbox
• Build YANIHP in scratchbox, as normal, with the following options:
  • EMBEDDED_FIXED_DATA_PATH=/home/user/.yanihp - this changes where the database, coverart, and lyrics are stored
  • EMBEDDED_FIXED_MUSIC_PATH=/media/mmc2/Music - this just changes the default location, the user's asked if they want to change it
  • EMBEDDED_USE_FIXED_PATHS=ON - enables the above two options
  • EMBEDDED_LEFT_BUTTON_CONTEXT_MENU=ON - makes it so that left clicking on the tray icon shows the context menu instead of showing/hiding YANIHP
  • WITH_Mpris_PLUGIN=OFF - not strictly neccessary, but I doubt you've got use for it
• Copy it across :)

There's a few caveats:

• It's only currently usable with the CleanLooks Qt theme - with small font sizes and so on, not with GTK support.
• Phonon-gstreamer doesn't appear to support manually switching between gstreamer audio sinks - in particular, there's no mp3 codec as such - instead, you need to connect your audio source to "dspmp3sink" instead. Alternatively, you can use another phonon backend.

I'm not uploading packages, as I've got no idea how to make a "good" debian package.