Recycled Plastic Water Bottle and Paper iPhone Amplifier: Use a empty water bottle and paper to make this simple, effective iPhone speaker to amplify the sound. It can be double as an iPhone kickstand for watching movies.
Image of Cool Things to 3D Print: Hex Phone Sound Amplifier
iPhone Speaker made out of PVC and an Old Bike Horn: To make one is very easy if you have an old bike horn. You’d be surprised how much sound you get from this little guy, which makes it the perfect noise machine for your iPhone.