1. Install Software Data Cable on Android. This is an FTP server for your phone, so you can easily see files on the phone and copy to/from your computers.
Another choice is the excellent ASTRO File Manager, which has a SMB (Windows network file system) module.
2.Start Software Data Cable. Press "Start Service"
3. In Ubuntu, open the URL given in step #2, like ftp://192.168.11.148:8888/ If all is well you'll see a listing of Android application folders, like "camera360".
4. To sync files, drag and drop using the above file manager, Nautilus. Or use "wget" which understands FTP. The following says "make a copy on my PC of all JPG images stored on the SD card on the phone. Keep all directories the same."
wget --mirror -nv --accept jpg ftp://192.168.11.148:8888/ .
If things don't look right try the above command and leave off "-nv" to make things more verbose.
Note that the above only gives you access to the "external SD card" parts of the Android phone. The other, "internal" flash are generally hidden. To access this area anyway you can enable it in Data Cable's settings area -- but this is sketchy and not recommended.