Rockbox is great.
I was able to increase playback speed without any chipmunk voice.
I enabled TIMESTRETCH, which allows one to change playback speed wihtout it affecting the pitch of the recording.
Installation instructions for Sansa Clip v1 here: http://www.rockbox.org/wiki/SansaAMS#Installation\_for\_Stable\_e200v2\_F
Manual is here:
March 20, 2010
pdf 916 kB
html-zip 517 kB
online
Thank you, Rockbox!