I used to go to a coffee shop in Clackamas somewhere which served up what amounted to a 32 ounce cup filled with nothing but strait shots of espresso.  It took a while for them to brew that much espresso, but man, what a rush.  I ordered it a couple times, and both times I went through "phases".  Start off nice and jittery, kind rushed.  Typical caffeine effect.  Then a sort of panic set in.  It felt like I was going to die.  My emotions would be all jacked up.  It would get really scary, then I would end up in a real calm mood, not really able to think straight, but at the same time, not panicky or jittery anymore.  I would be like that the rest of the day.  Sort of in a poetry mood.
Drink itself cost about 13 bucks (as I recall, it's been about 5 or 6 years).  Definetely would do it again If I found a place that served it around where I live now.