I was wrong and this FAQ tells me that after sync files will be moved from the 'latest' folder to 'synched' folder. To sync again I'll have to manually move files!
Something new to learn everytime mistake is made. Apple disabled the feature to enable iPod Touch 2G for disk use at iTunes so I can't move files/data using Finder or at Terminal. If you need to view hidden Unix files you'll have to do this, more about that from here
defaults write com.apple.Finder AppleShowAllFiles YES
Then I need DiskAid in order to gain access into the file system of my iPod Touch 2G.
Alternatively you could dump Nike+ all together and upload your run data to RunnerPlus. To do that you'll need Yahoo Widget Engine and their desktop widget. It supports Mac OS X or up to Windows XP only. In my view the graphic isn't as good as Nike+ but there are other resources which you may find useful.
Now I have retrieved all my run data so far.