The act or reactive measure when the opposite sex makes eye-contact with you and then proceeds to plug in their iPod as a defense mechanism to prevent you from making a move on them.
Josh: I saw this girl on the bus and was going to hit on her, then she busted out her iPod.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.