EphPod

From TrentSoft:

EphPod is a full-featured, easy-to-use Windows application that connects with Apple's iPod. With a FireWire card and EphPod on a PC, it takes under 30 minutes to transfer 1,000 songs to an iPod. In addition, EphPod supports standard WinAmp (.M3U) playlists, includes powerful playlist creation features, and will synchronize an entire music collection with one click. EphPod also includes powerful music-information ("tag") editing options, as well as support for Audible and MP4/AAC files (although not the "protected" MP4/AAC files sold at the iTunes Music Store). EphPod is designed to be completely compatible with iTunes, so that you can use both EphPod and iTunes interchangeably with your iPod.