Glucose Tolerance Test - the basic one, you pop along to phlebotomy and they take your blood, you drink some lucozade (yuk!), then they take it again an hour later. If this test indicates diabetes or is a bit "is-she-isn't-she?" then you get a two-hour fasting test... but most GTTs are normal.

I'm having to do one in a few weeks, I just hope I'm still working here otherwise I'll be having to go out my way to do a stupid test!