Follow the source link and it will show you an official tutorial. (Or the second link, if you’re better with following pics)

Enjoy the ease of reverse sync!
References :
http://support.microsoft.com/kb/948835
http://www.zunescene.mobi/forums/index.php?topic=47981.msg561153

I think its step by step guide is most helpful.
http://iphone-to-computer.net/transfer-songs-videos-photos-playlists-from-ipod-to-computer-itunes.html

It is easy to use and you can try it now.
References :

Hi, I recommend an iPod to computer iTunes transfer software.

http://www.ipod-to-ipod-touch.com/copy-songs-videos-photos-playlists-from-ipod-to-computer-or-itunes.html

It can help you copy songs videos photos playlists from iPod to computer or iTunes in a couple of clicks. If you own more than one iPods, it can simultaneously manage all the iPods in the same interface, you may transfer files among these iPods by drag-and-drop.

Hope it helpful for you.
References :

http://ipod-tool.com/ipod-software/joboshare-ipod-rip.html

It was designed to help transfer music, videos, photos, playlists, podcasts and more from iPod to computer and iTunes. So you can use it to transfer music from your iPod back to your iTunes in a direct way. Then all files are on your iTunes, and you can sync smoothly without deleting any files.

This is easy and quick. I recommend you try it.
Best luck!
For more iPod instructions, use http://google.com
References :

Many of my friends recommended it to me when I needed to transfer all my songs, videos, playlists, photos podcasts etc. from my iPod to my iTunes.
With just a few simple clicks, it will help you transfer all songs/videos and other files from iPod to iTunes as well as from iPod to your selected folder on your computer.
More importantly, this won’t overwrite any original files on your iPod. And all song names and playlists are preserved.

Hope this can help.
You can also search more others at http://google.com
References :

It even has step-by-step guide on the whole process.
Hope it helps.
You can keep asking on http://answers.yahoo.com or use http://www.ask.com to search more
References :

http://www.dvd-video-tool.com/ipod-transfer.html

Key functions:
1.It can backup your iPod files to computer and tranfer music/video/photos from local files to iPod without iTunes.
2.It can transfer your iPod files to iTunes and another iPod.
3.It can manage your iPod as a hard disc.
References :

◆◆◆◆◆◆◆◆
Key Function:
1: Transfer/Share iPod files from one iPod to another iPod.
2: Transfer/Backup iPod files from iPod to your computer.
3: Transfer/Backup iPod files from iPod to your iTunes.
4: Manage your iPod like an harddisk.
5：Transfer files from your PC to your iPod.

◆◆◆◆◆◆◆◆
With this useful tool you can transfer your iPod files between iPod and iPod, iPod and Computer, iPod and iTunes easily and fast.
Just try it and hope it can help you.
References :

With it you can:
1: Transfer iPod files to Computer
2: Transfer iPod files to new iPod
3: Transfer iPod files to iTunes
4：Transfer local files to iPod without iTunes
5: Manage your iPod like a movable hard drive and transfer ipod videos/photos/music between iPod and iPod, iPod and computer/laptop, ipod and itunes.

You can find it here:

http://www.topmediasoft.com/ipod-transfer-avcware.html

this iPod to iPod/computer/iTunes transfer fully supports the latest iPhone OS 3.0, iPhone 3GS, iPod touch FW 3.0, and iTunes 8.2.

It is easy to use and you can try it now.
References :