Kitty - I had gestational diabetes in my first and second pregnancy. I failed the test in my first, but passed the second but started to develop high sugar readings from testing my sugars after food later in the pregnancy.
As far as I'm aware, we have to sit for two hours afterwards and not allowed to walk around. I totally agree with you though, because really, who eats and sits for two hours straight? I'm definitely not sitting in the waiting room tomorrow morning with two small children screaming and running around, I'm going to go home and at least sit in my living room!