Can You Sync An Ipod To More Than One Computer?

The problem is if you try sync in the more than one system,the existing stored photos linked to the previous system folder will get deleted and den sync with the second system takes place.

I think it is ok if you wanna use your iPod as a hard drive without running the relevant iTunes . It is safe for your iPod as long as turning off iTunes or its auto sync. If you are using the iPod on more than one computer,then set the iPod to "manually manage songs and playlists"(edit->preference->device->disable the auto sync for all iPod and iPhone)and this will keep it from automatically synchronzing with iTunes and erasing all of the songs on the iPod.
And if you wanna use your iPod in different computer and also wanna import something you like but exist in the other iTunes on another computer ,the third party program would be pretty useful to make it. Use sort of transferring program to make an iPod content transferred to the anotheriTunes and then sync it to the another iTunes. Then you can get other content from another iTunes on another computer at the same time maintain your own content still on your iPod.

iPod to iTunes transfer application,iTunes backup tool