The rock is my favorite. I LOVE the patterns in the cracks in that rock. I know what Limr is talking about in the processing. These look kind of over-sharpened or something, like maybe the sharpening applied on export was set for Print/Hard, or something...the content on the first three is lovely, and the lenswork seems good. I'm not fond of the shallow DOF and the edge quality drop-off on the tree shot, but all of them seem like the sharpening is wonky. I thought keyseddie's comment about "pushups in the morning" was really appropriate to these; these are like visual exercises, and I don't think any photographer worth his salt would skip over this great subject matter. You just gotta take these kinda shots.