Try the pitch/tempo preset in the NSPS DSP
- Winamp > Ctrl+P
- Plug-ins > DSP/Effect
- select ' Nullsoft Signal Processing Studio DSP' > Configure button
- LOAD button > select 'justin - simple pitch and tempo (half-2x) control.sps' > Open button
- don't forget to checkmark 'Enable procession'
Or use a third party plug-in. Pacemaker
is one of more suggested plug-ins. Unlike the preset in the NSPS DSP, Pacemaker will let you change the tempo ("speed") without changing the pitch ("sound"). In other words, plays fast but sounds normal.