Not so long ago as I finished university, there was a drug doing the rounds called Modafinil.

It is prescribed for narcolepsy and when taken can greatly improve concentration and delay or even eliminate the onset of tiredness. It has a different mechanism to traditional stimulants - coffee, red bull, etc

I just wondered if anybody had heard of it being taken here either by students or in the workplace? Given the working culture I wouldn't be at all surprised.