The latest GParted 0.8, released a couple of days ago, adds an option to rescue data from lost partitions: "This new feature uses the gpart command to guess the partition table. Discovered file systems can be mounted read-only so that you can copy data to other media". Bugs fixed in the new version include: fix paste destination partition smaller than source, prevent visual disk display area from disappearing and fix minor cylinder alignment rounding error. A complete changelog can be found HERE.