
The Overdrive Pedal Comparinator is a fun online application that allows direct comparison of several types of overdrive pedals. You select two pedals, then load them into the app, which plays synced prerecorded mp3s of each pedal, toggling between them seamlessly.
While the pedal selection is limited at the moment, there are enough available to keep you occupied for quite some time on a cold night.
Check it out: OD pedal Comparinator