From The Office Maven:
iTunesMyPortable is a Windows based add-in utility for iTunes that allows you to synchronize the music and videos you have stored in iTunes with virtually any portable audio device that can be accessed as a Mass Storage Device (a device that appears as a drive letter in Windows Explorer). In our opinion, iTunes is one of the best music organizers on the market today. Unfortunately, iTunes doesn t directly support the synchronizing of your music with a Mass Storage Device (MSD). This means that there is no way of synchronizing your portable audio devices (Sony Ericsson Walkman phones, Sony PlayStation Portables, and portable music players.) with the music you have stored in iTunes. Fortunately, iTunesMyPortable can come to the rescue and solve this problem for you. With iTunesMyPortable, you can synchronize your portable audio device with iTunes just as if it were an iPod or iTunes Mobile Phone (A.K.A. ROKR ).