Mmm, it looks like the basis for a great signature.
Decrease the contrast - while I do like contrast, the one here is a tad too hard.
Use transparency - let the San Fran fly out of the picture, same way as I did with Lunaphase and Eternal's sigs.
Move the text. Right now, it just sits in the middle of nowhere, disrupting the otherwise nice composition of the picture. Should you include transparency, move it into a transparent are where it doesn't disturb the image flow. (also, maybe use another font or shadow filter).
Add stuff in the black background. Not too much, but some decent, far-away stars would be great, I think.