Amazon.com: Mate2GO Phone Stand Sound Amplifier, Wood Phone Stand for Desk, Desktop Phone Stand, Phone Speaker Amplifer Holder, Handmade Wooden Phone Dock Compatible with Smartphone, Kindle, Mini Pad - Beech : Cell
Amazon.com: Passive Wooden Phone Speaker iPhone Amplifier made from Red Toned Ash Wood : Handmade Products
How to Build Cell Phone Speaker Amplifier : 10 Steps - Instructables
How to Make Speaker Amplifier for your Phone - DIY iPhone Smartphone Speakers - YouTube
DIY phone speakers that rock (and a few to avoid) - CNET