Memory Erasure Pill

Long term recall (of events, at least) works by destroying the original memory (according to what I read in Brain Rules). In the normal course of things, the memory is refreshed (stored again). Supposedly you can soon take a pill which blocks the saving of memories retrieved. Careful not to think of any fond memories until it wears off :)

via (disclaimer: Wired magazine, so expect techno-hype)