First, a disclaimer: this is a peripheral no one wants, but many will need. The Belkin Headphone Adapter for the iPhone simply allows you to do what you should be able to do without any adapter whatsoever -- plug in a plain ol' set of headphones. This was a pretty clear-cut play on Apple's part to give itself and official accessory manufacturers some license to further scar our already irreparably damaged wallets, and frankly, we're bitter that we had to buy it for a stiff $9.95. But yeah, whatever, let's get on to the good stuff.
Attaching the adapter made us even sadder than we already were. It adds considerable length to the already long device, and it's just barely flexible -- not enough to bend more than 30 degrees or so without getting concern that you're going to break it or the jack. What's more, it looks completely and utterly out of place.
To be fair, though, it gets the job done and the sound quality is great. You won't be able to use a phone headset with integrated talk button and mic, but since the iPhone's just as much an iPod as it is a phone, we consider it our civic duty to attach some decent 'phones to it.