Apple polishes up its new line of iPods

— -- Still, the latest improvements are welcome. I'm most jazzed about a music-discovery tool in the new iTunes 8 boldly called the Genius feature, which creates automatic playlists from your music library based on a song you select. It's kind of like Pandora or other personalized Internet radio — except you don't have to be online.

Shaking the Nano to make something happen is just one feature lifted from the iPhone and iPod Touch. The other is the motion sensor, or accelerometer, that lets you access Cover Flow just by rotating the Nano to its side.

First introduced in iTunes a couple of years ago, Cover Flow lets you pore through your library by album artwork. As with the iPhone and Touch, you can change the orientation of a photo to landscape on the new Nanos, just by turning the device to its side.

Here are a few quick impressions of the new gadgets:

•Nano. Thinner than ever, the 1.3-ounce Nanos look more like first-generation Nanos than the square versions they supersede. I actually prefer this taller design. Apple retained the same 2-inch screen, now covered by curved glass. The device comes in nine colors; an 8-gigabyte version fetches $149; the 16-GB Nano is $199.

You can create Genius playlists on the fly. I was unable to test Apple's claims of 24-hour battery life for music and four hours for video.

•iPod Touch. As before, it's like the iPhone without the phone (or camera). It uses Wi-Fi to let you download items from the App Store. The new version's thinner, more contoured. There's a physical volume switch on the side, one thing Apple says consumers asked for. It, too, lets you create on-the-go Genius playlists.

There's also a built-in sensor for the Nike + iPod Sports Kit which runners can use to track pace, time and distance. You must still buy a $19 sensor that fits in your Nikes. And you'll have to splurge for the shoes.