The coffee house across the street from UNLV used to make this concoction they called a Mocha Shake. It wasn't fancy. They just poured a cup of fresh brewed espresso into a softserve chocolate milk shake. Short and quick, but tasty. In and of itself it was fairly potent. For those extra hardy, need-to-stay-up-longer types they had an unadvertised special. For a couple extra bucks they would add two or three extra cups of espresso and then dump in some grounds for good measure. One full size drink like this had me up for something like 30 hours and I swear I could see the molecules dancing in the air. Caution; this sort of drink isn't for the weak, It can either keep you awake or send you into an immediate adenosine crash.