BuyDig offers the Lexar 16GB JumpDrive TwistTurn USB 2.0 Flash Drive 4-Pack in six colors for $18.99 with free shipping. That's $4.75 per drive, tied with our mention from three weeks ago as the lowest total price we've seen. (It's also a current price low for this quantity by $5.)

Note that the other colors are available under “More Options".