To reuse or not to reuse?

A ceramic mug may seem a more virtuous choice than a cup made of polystyrene, the foam banned by ecologically conscious local governments. But it takes much more energy to manufacture the mug, and then each washing consumes more energy (not to mention water). According to calculations by Martin Hocking, a chemist at the University of Victoria in British Columbia, you would have to use the mug 1,000 times before its energy-consumption-per-use is equal to the cup.

... A more immediate environmental impact has been demonstrated by studies in restaurants: the average number of bacterial organisms on reusable cups, plates and flatware is 200 times greater than on disposable ones.

Source: Recycling is Garbage