When Steve Jobs introduced the iPhone, he said it was the "best iPod ever". In many ways, he was right; for example, the larger screen and touch-screen content browsing are stellar. On the other hand, the iPhone also has something in common with the worst iPod ever, the third generation (3G) model: touch-sensitive playback controls.
Don't get me wrong; touch-sensitive controls can be very cool, and very effective witness the iPhone's overall interface. But when it comes to portable music players, there are times, such as when the player is in your pocket, when these controls are a major hassle.
For starters, there's the whole "Oops, I didn't mean to touch that" thing, when you stick your hand in your pocket or bag and accidentally brush against a control, skipping tracks or, even worse, turning the volume to full.
But even more problematic are situations when you want to do something for example, skip to the next track but the iPod is out of sight. With physical controls, you can feel around for the right button and press it. With touch-sensitive buttons, that's not an option. This is bad enough when the controls are touch-sensitive but tactile, as on the 3G iPod you end up accidentally "pressing" random buttons while trying to feel around for a particular one. It's even worse when all the controls are part of a single, flat surface you have no other choice but to pull the player out, turn on its screen, and visually locate the desired button.
This isn't just idle criticism. As much as I love the iPod section of the iPhone, after using it for a couple weeks, I'm already frequently annoyed by this drawback. Sure, the iPhone's earbuds include an inline controller, but it provides only the most basic functions. (And if you prefer better headphones, you're completely out of luck unless you buy a third-party accessory.)
In my opinion, any good media player must have a few essential physical controls: play/pause, volume up/down, forward/back, and hold. And these buttons must be usable by feel. With rumors of upcoming touchscreen iPods multiplying by the minute, here's hoping Apple doesn't go overboard with the whole "Ooh, look at the touchscreen!" thing, and makes the next iPod both drool-worthy and usable.