Gizmodo plaid with the new Samsung Ultra Music SGH-F300 at CES 2007. Here's a snip from their report:
The 9.4 mm-thick candybar's double LCD design is pretty revolutionary: There's one on the "phone" side, and a larger one on the "music" side, which supports MP3, WMA and AAC. You switch between the two screens with a button on the side of the phone. (On the other side is the SIM card slot, which is behind a rubber top just like the microSD one, so it can be swapped out fairly effortlessly.)
What's nice is that music is easily accessible: just pop in a microSD card (or use the 400 MB of internal memory), navigate to the music icon (the multimedia menu reminds me of a PSP, so it only takes a second) and hit play. Displaying the album art is a nice touch, making it feel more like a real music player. The entry pad on the multimedia side is very much like the Chocolate's, with no tactile feedback, but it felt fairly responsive. It also, as you can see, gets smudgy after only a second of manipulation, but cleans up with a quick swipe of your sleeve.