For those of you who still cling to the outdated and utterly Neanderthal concept of dedicated MP3 players (snicker) you may find it useful to know that the latest build of Rockbox has been released. Rockbox, for the uninitiated, is an open source firmware for a collection of deadbeat misfit MP3 players.
As far as the devices I've used with it have gone, it's turned good players into absolutely fantastic players, much like a swap of OS can make a poor computer great again. Few manufacturers (if any) would spend the time to optimise their codecs to save battery life and increase performance, but Rockbox does it! Heck, is there any player maker that includes as many features as Rockbox supports without requiring you to step up to something fancier, like those mini-tablet/half-smartphone devices?
On my Sansa Clip+, Rockbox increased my battery life (especially while using OGG Vorbis), gave me a less pretty but more intelligently designed UI, allowed me to swap out themes, let me play many more codecs and file formats, gave me a more stable MP3 player all-around (especially when it came to the battery life meter, which is actually reliable now), and made the Sansa Clip+ an MP3 player in a class of its own. Oh, and the clock is accurate and everywhere, saving me the trouble of finding another device that displays the time.
If you have a music player and it is supported in the latest Rockbox, I cannot recommend installing it enough. If you're all about prolonging the life of your technology, this is the sort of software that should delight you.