According to the Death by Caffeine calculator, I can drink 117.39 shots of espresso before the caffeine content would kill me. I think I’m safe (but I’m not currently on a book deadline). Choose your drink, enter your weight, and find out for yourself!

Hmm I work at Starbucks currently, largely for the free coffee, which is worth more than they pay in monetary value without question. I don’t think I’ve gone a monday-friday in the last few months without averaging 10-20 shots of espresso a day. Sometimes I’ve hit near 40 in a given day. Free is free, after all.
I suspect I could give this death by caffeine calculator a good run for it’s money.