The GiraDora is a pedel-powered washing machine: http://inhabitat.com/human-powered-giradora-washer-needs-no-...

There are other concepts which are more bike-like: http://webseriesnetwork.com/photo/pedal-power-washing-machin...

I've seen similar things in Africa were people just attached bikes and drums together. Didn't have hot water though. For cold water + soap washing it's clearly a win.