For those of you that are into caffeine and want to know what is the best drink to get, these guys have done a study, and detail flavour, composition, density of caffeine per ounce as well as how much total caffeine there is in the drink (for those of us too lazy to take oz * caffeine/oz).
Interesting, stuff, like penguin mints have 7mg of caffeine per mint and 3 of them is equal to one 12 oz soda (like coke). The thing to remember is that the LD50 of caffeine and it's chemical info is detailed here.
What's LD50? It's the Dosage of caffeine someone can take and die only 50% of the time. And for caffeine in rats, it's around 179 to 200mg per kg. So if you are a beefy boy, and weigh around 180kg you'd have to drink around (at LD50 200mg/kg) 200 16oz cups of starbucks brewed coffee.... Yeah it's gott 200mg per 16oz cup. Which is about 25 GALLONS.
Oh and this is a neat site about coffee, the Coffee Faq. It may not be CoffeeGeek but it's a start.