Can you overdose on caffeine?

I've got so much caffeine in my system its not funny. I've taken migraine medicine (120mg), half a pack of Mad-Croc gum (160mg) and 2 liters of Mountain Dew (310 mg). Thats 590mg of caffeine... acute overdose is 400mg. I better stop. Good thing a lethal dose is a whole lot more than that.

That gum tastes like shit by the way.

God I hate eBay's API. It sucks hardcore.