The MP4-21 from Shenzhen Sietek Industrial offers a new take on Apple’s clickwheel. The device supports MTV videos, WMA, MP3 and WMV audio files (with ID3 tags) and JPEG images, and has seven EQ modes. A 2.4-inch TFT screen that displays 262,000 colors, some kind of USB port, and a miniSD slot are built-in. For Windows 98, ME, 2000 and XP.