We're typically appreciative when companies make bold design choices, but id America's Gasket ($30) and Skyline ($25) cases are on the fine edge of taking the idea a bit too far. The Gasket is a brushed aluminum case with foam lining, a design that will most likely be radio-neutral with iPhone 4's widely-publicized antenna problem while leaving a substantial portion of the phone's rear glass surface exposed; front and rear film is included to help…