The idea is simple: Apple’s recessed iPhone 3G bottom speaker is extremely easy to cover with a finger during gameplay. Attach the black glossy plastic SoundClip to the iPhone’s Dock Connector port and it adds a little “passive sound enhancer”—read: a molded plastic cup—to the device’s bottom. All of the sudden, no matter how hard you try or where your fingers wind up, you won’t muffle audio that comes…