$10.00A cheeky, modern day spin the old-fashioned wind-up gramophone! Slip your iPhone into the base of this adorable, portable amplifier and let 'er blast up to 13 decibels of volume with no external power needed. These soft and lightweight silicone rubber cuties hold your device horizontally or vertically while an additional opening allows you to charge at the same time. Washable and scratch- and dirt-resistant.
Have you heard about the cup trick? You can amplify your built-in-iPhone-speaker's volume by resting it in a dry glass cup. It's called a "passive speaker," and it works kind of the same way that the hollow body of a guitar or violin helps to amplify the sound made by the strings. Of course, leaving your iPhone in a glass isn't the most gorgeous solution for amplifying sound without extra power.