I reuse them until it becomes mildly discomforting at which time I know the lancet has dulled. Of course AccuChek prefers that you use it once;)

I have been mostly reusing (up to a point) both the lancets and insulin pen needles. I don't go overboard, i.e .weeks, but ... how much contamination is possible? well... i never reused syringes, however. The idea of doing that makes me wary.