Acoustically amplify your iPhone or iPod by 200% to 400% with the Koostik ($90)! Developed from years of research, the Koostik is handcrafted from solid wood to provide you a simple yet effective design that follows the same principle as an acoustic guitar, where the sound is magnified through its hollow body. Simply place your iPhone or 4th gen iPod in the center cradle, and you're ready to rock!