It's a kind of seltzer tablet. You drop one into your favorite tangy drink (I use Diet Snapple and Diet Hansen), wait 5 minutes, then turn the drink into an instant Red Bull. :D :D Okay, maybe not the Red Bull, because Umph lacks some of the `good stuff' in Red Bull like taurine and guarana, but it's still got 99mg caffeine (cf. 75mg in Red Bull -- 33% more!), 40% DV vitamin B6, 30mg ginseng.
And it's potent as hell. And cheap -- 45 cents per tablet when you buy a 20-pack for $9, as opposed to $1.33 per can of Red Bull when you buy a 24-pack at Costco; you just find a soda cheap enough (under 88 cents/can, which you can easily find when you buy in bulk).
It's a blessing. Especially those who can't stand the `medicine-like' taste of most energy drinks.
Oh, and a bit of caution. You need a big cup if you use it with any type of soda; don't ever try to drop Umph directly into a soda can -- Umph generates loads of carbonate fizz, and you know the consequences. Taking a couple of sips off the can does not help. I learned it the hard way this morning. ;_;
For more info: http://www.try-umph.com/. As of now they sell a 20-pack for $9 plus tax, and the shipping is free.