The Register's taken an "interesting" ;) angle on this one. Insert tongue in cheek. Then read...
Litterbug astronauts have hurled almost a ton of junk off the International Space Station, including an old refrigeration system weighing 1400lb, risking a fiery meteoric death for innocent Earth-dwellers. In sharp contrast to green consumers worldwide, NASA has brazenly revealed that the fly tipping spacemen hadn't even used the fridge before throwing it overboard. Outrage is expected from the sandal-wearing, lentil-friendly elements of society.
More: http://www.theregister.co.uk/2007/07/24/space_fridge_dump_shocker/
A slightly more prosaic report can be read here: http://www.nasa.gov/mission_pages/station/expeditions/expedition15/e15_eva_072307.html
An old fridge thrown off the International Space Station last year is set to re-enter the Earth's atmosphere shortly, according to reports, delivering a volley of 100mph space frag debris to an as-yet unknown impact site.
The refrigeration unit in question is the Early Ammonia System (EAS), a 1400lb tank intended to furnish backup supplies of the unpleasant-smelling coolant to the space station in the early stages of its construction. As the ISS neared completion it became surplus to requirements.
More: http://www.theregister.co.uk/2008/11/03/eas_iss_fling_plunge_debris_arrival/