The n800 has quite a few media players already, and they all have their good points. None, however, seemed to be very useful, or indeed easy to use, while walking; if you want to change song, they all need you to get the n800 out of your pocket, unlock the screen, tap a button, lock the screen again, and put it back.
Having gotten tired of this, I decided to write a media player that worked for me while walking - and did virtually nothing else. The result is Spindle.
For starters, there's no fiddling around with playlists; you just select the songs/albums you want, and hit play. If you don't like the song, you can skip it, but there's no going back (so make sure you have at least 50% good songs in your selection!). Selection is done via a large, finger-friendly interface, with album covers for instant visual recognition.
The best part (and only other real feature) is the 'locked mode'. Hit the <- button, and the program locks the touchscreen, but not the hardware buttons. You can still hit Fullscreen to skip songs, and the center of the D-pad to play and pause, and you don't have to worry about stray clicks on the screen while the device is being jolted around in your bag/pocket/whatever.
I must thank Urho Konttori for some of the inspiration here; the UKMP sourcecode has provided a excellent jumpstart to getting things like GStreamer working from within Python. There's no verbatim copying, but there are a few areas of similarity (I did think about submitting patches to UKMP, but it's too away from what I am looking to create).
I'll be releasing an initial beta version soon, so keep a look out.