b3nn3tt said:
Quick Wikipedia search says that the LD50 (point at which half of subjects would die) is 150-200 milligrams per kilogram of body mass.
That's roughly 80-100 cups for an adult male. You'd have to drink that within five hours or so though, depending on metabolism, as that is roughly the half-life of caffeine
Heh I just pulled out a calculator for this; if your numbers about the lethal dose are correct then you'd have to drink just under 44 litres of a typical energy drink (32mg/100ml) to get that amount of caffine into you. Which would be impressive.
I'm not quite up to 44 liters yet, but I did once down 6 cans of Monster at once (long day biking on no breakfast, good times) without any particularly adverse effects. Slight experiance of time dilation, which was awsome, though that was likely just psychological. I was convinced that ammount of caffine had to do
something.