I bought a bottle of creatine about a year and a half ago and it has sat in the bottom of one of my desk drawers since. This thread made me think of it, get it out, and since I road into work today on my bike, I decided to take a couple to see what the effects, if any, would be on my 2 hour long commute home. The bottle looked almost full and I couldn't remember specifically why I had never taken a them after first buying them.
I am an idiot.
After an hour, my thighs felt like they had been beaten with a ball peen hammer. It could be the placebo effect or the power of suggestion of Creakyknees' "crampy" post, but now I think I know why I hadn't used up the bottle.
To the OP, I suggest you buy a small bottle and give it a try. This is something you want to experience first hand yourself.