meh, at least its better than nothin'. Try making the background a dark color, I perfer black. Throw in some colors to make it look more rainbowish(if thats a word) just like the text on top of your sig. I'll give you an 8/10 for the effort.
it's pretty good for a first attempt in photoshop. it would look nicer if you made the background a bit darker. maybe you could try duplicating the background layer and set it to multiply or something. I'll give this a 7.5/10 :]
Nice job on the first attempt, but I agree with Xe54. A darker shade as your background will help. Playing around with your subject (namely, the render) like messing around with brightness, color balance to get the subject to at least blend with the background would be my second suggestion.