Bottomline: It's a shame that it's car-only but the iTrip Auto works well.
Devices such as this, which allow you to broadcast your iPod over FM radio waves, have been around for a while.
It's only since the Government changed the law that they've been legal, though: because they can interfere with normal radio broadcasts, the government used to frown on them. The iTrip Auto doesn't use much power, though, so it's unlikely to interfere with much outside your car.
It draws power from the car's cigarette lighter socket (there's no mains power connection or removable battery so it can't be used outside the car) and charges the iPod at the same time. Annoyingly, there's no connection for anything other than an iPod. It's easy to use – there are three buttons on the main unit, along with a clear display.
The Smartscan part of the name indicates that it can pick up little-used frequencies. In practice, this worked reasonably well – although the frequencies it picked were congested with other broadcasts. It certainly makes it easier to use than older models on which the user has to pick a frequency by trial and error. It is, of course, still possible to select your own.
Quality was impressive, with clean and clear transmissions, and you can switch it to mono (as opposed to stereo) operation, which boosts its signal if you can't find a clear transmission. Of course, it's much easier overall to plug your player straight into the car stereo, but for iPod users without stereos that can accept inputs, this is as good as it gets for in-car music.