How to Listen to a Sansa While it is Charging
Found this on eHow.com and was skeptical that it would really work with my Sansa Fuze, but low and behold it does! Basically, after connecting the cable to your Sansa, you just slowly plug the USB cable into your PC. Watch for the charging indicator on the screen. The charging pins–for some reason–connect before the data pins do. The directions say to then plug the cable completely in, but I have found this isn't necessary.