gimp-ufraw (ubuntu hardy) would open cr2 files from my new camera (Canon
Digital Rebel XSi, aka 450D), but until I applied a patch the colors were all
wrong. (This is on launchpad but
not fixed in an official ubuntu package yet)
Another nice tool with this camera is gphotofs, which allows the
camera to be mounted as a filesystem even though it uses PTP rather than
mass storage. The one packaged for Ubuntu Hardy works nicely.