Cables and batteries are a bother that we just have to live with until wireless power comes along, right? Or do we? This gadget called the AirCurve Acoustic Amplifier manages to amplify the sound from your iPhone’s built-in speaker, increasing the volume by around 10 decibels – without needing any power. We have high-tech mathematical engineering to thank of course, plus a little old-school inspiration (think the big brass horns on old gramophones). Letting you enjoy full-sized speaker sound absolutely anywhere, anytime and also useful as a loud, no-power-drain alarm clock, the AirCurve Acoustic Amplifier is available from Griffin Technology for $19.99.