The Griffin Navigate has no dials, of course, but it does bring FM radio to your iPhone (and just about every iPod model, too). It also adds tactile playback controls, effectively solving what is arguably the iPhone's sole interface problem.
For example, when you're listening to music and want to skip to the next song, you have to fish your iPhone out of your pocket, turn it on, unlock it, and then tap the next-track button. And if you've ever tried to rewind 30 seconds in a podcast or audiobook, well, you know how much fun that isn't.
The Navigate sports Play/Pause, Volume, and Shuttle buttons. There's also a Mode button that cycles through various features (including an equalizer!), all of them represented on the gizmo's two-line OLED screen.
Of course, for navigating the FM spectrum, you may want a screen that's a little more generous, hence Griffin's forthcoming iFM app. It identifies your location and lists nearby stations for one-tap tuning. Alas, company reps couldn't say for sure when it would debut in the App Store. Best guess: "Soon."
The Navigate has a list price of $59.99, but with a little Google searching you can find it for under $40. If you've ever wished for tactile controls for your iPhone or just an easy way to tune in your local NPR station, that may seem like a bargain indeed.