I really like Rockbox (an alternative open source firmware for some portable media players). It's usually much better than the original firmware. However, it sure is getting bloated. The recently released version 3.0 only leaves 1.12 MB of buffer* when running in RAM on my Archos V2 Jukebox Recorder. The bloat might not matter on other platforms with more memory (such as the Video iPod, which has 32 or 64 megs) but it has gotten to the point where it might be best to run an old version on platforms with less memory, such as the Archos devices which only come with 2 megs. I'll continue running my old version from November 2007 which I stripped down and put into ROM, resulting in 1.735 MB of buffer.
* The buffer is filled with MP3 data from the hard drive. Then the hard drive is spun down and data in the buffer is played. When little remains in the buffer, the hard drive spins up again to refill the buffer. If less buffer space is available, the hard drive needs to spin up more often to refill the buffer, resulting more power usage and more wear and tear on the hard drive.