Today only, 5StarDeal offers the MistyMate Twist and Mist Deluxe Cooling System
for $5 plus $2.99 for shipping. That's the lowest total price we could find by $5, although we saw it for a buck less three weeks ago (since expired). This 5-foot mister features two brass and stainless steel misting nozzels, 3/4" hose adapter, and more. It purports to cool the air by up to 30 degrees.
Update: Even better, THAT Daily Deal has it for $4.99 plus 99 cents for shipping.