One, if I did that it'd be too much like work and not as much fun; two, I don't have enough time to search the Web for new and interesting pictures every day; three, there isn't as much variety in the geological pictures available on the Web as for astronomy; four, every time you put a picture on FreeRepublic from a different site it takes up quite a bit of bandwidth and I don't want to do that consistently.
But thanks for asking. This last picture generated some nice response.