Olympus digital voice recorders (check online manuals before you buy), I have an old one, DM-5 that allows you to change the playback of MP3s from 50% to 600%!

Olympus digital voice recorders (check online manuals before you buy), I have an old one, DM-5 that allows you to change the playback of MP3s from 50% to 600%! only minus with this is friggin slow startup if you add a lot (over 1000) MP3s plus bit PITA to use under linux.