When you plug in a digital camera on an Ubuntu system, Gthumb is the default tool to import your shots. I prefer F-Spot over Gthumb because of the tagging and webexport functions. To change this default setting to use F-Spot instead of Gthumb do the following:

Click on System > Preferences > Removable Drives and Media. Go to the Cameras tab. Change the "gnome-volume-manager-gthumb %h" command to "f-spot-import %h".

The next time you attach your digital camera or a photocard, f-spot will be used for the import.