I'd have to agree with DR on both counts. You can usually tell where the lighting should be by looking at the shadows on the render or stock. I liked the smudging on the first one, but some of the effects look choppy :P

Also, when resizing an image, make sure to hold the shift key (if your using Photoshop). It looks like you smashed the image a bit on the second one, or maybe it was like that? There's also a large empty white spot... Beyond that, the text is probably one of the hardest things to do in a signature (at least it is for me).

KIU buddeh :P