Diapid. [nasal spray]

Often listed under the category of so-called 'smart drugs'. It is said to: help aid in processing new memories; improve attention, concentration, and recall; help clear the mind when under the influence of other substances.

Marijuana and alcohol inhibit the release of vasopressin. Cocaine, LSD, and amphetamines deplete vasopressin.

A Short Introduction To Smart Drugs
(haven't checked this link)

Smart Drugs / Nootropic Info
(links page)