Edit timestamp vs. posted timestamp

Revmen,

Is there any way that posts can indicate the time and date when they were edited as opposed to only when they were originally posted? I've made some FAQ changes, yet to the unbeknownst, it looks as though our FAQ has remained untouched since the day we moved here in March.

Can this be changed, or is do I need to delete and re-post each topic if I want it to look current?

-- mrgraff