This is a really good signature. Great job, keep up the good work.
As Slothie said, the text isn't fitting in very well, although it is in a good spot. Text always looks nice for me if I put it as white with a black 50% opacity stroke on it. Font choice is also a big factor. www.dafont.com has tons of free, great quality fonts to choose from.
Hope this is helpful!
Edit: Try using the Visitor font at 13px on the signature.
That looks SO cool. As people have said, the text wasn't that great, still could use some work. I don't really like that grey strip there either, perhaps you could turn down the opacity even more?