Rosetta's operations team just handed us a couple of breath-taking images taken by the spacecraft's navigation camera (navcam). The camera is actually designed for navigation purposes, so they aren't to be compared with the full-colour scientific capabilities of OSIRIS - but they are amazing views!
This image was captured at 14:23 UTC (15:23 CET), when Rosetta was at a distance of approximately 236 000 km from Earth's centre. It shows a cloud-covered North America in some detail. (Click on 'Full story' for a second cool pic!) -- Daniel
This image shows a cloud-covered North America, and was captured at 14:03 UTC (15:03 CET), when Rosetta was at a distance of approximately 224 000 km from Earth's centre. It is not quite as nice as the first, and shows a few smears from the CCD camera output.
The navcam is used for precise determination of the orbit and optical visualisation. The output of the camera tells you where the centre of the object that is in the centre of the field of view is - it also gives physical parameters of the object.
The photos were taken to test the camera's operation with a large physical object. Previously, Steins was also imaged, but it is rather small (about 5 km across). Next year, the camera will be used to view Lutetia, which is much larger (about 95 km across). In the camera field of view, Lutetia shoudl appear about as large as the Earth looks in these images.