YamiPod is a freeware application to efficiently manage your iPod under Mac OS X, Windows and Linux. It can be run directly from your iPod and needs no installation. Take a look at the feature list to find out what it can do and feel free to suggest anything that might be missing.
[ADD] better support for new iPods (nano and classic)
[ADD] support for iTunes 8.x
[ADD] video can be added to iPod
Windows, Mac, Linux
Product page: here