Looks pretty good, first one would look better if the web address wasn't overlapping the background writing.
Also, i think it might look a bit better if you made the margin on each side even? eg you don't leave much space on the bottom of the cS logo but on the left and right the gap is a bit larger. maybe make those the same size.
I just think the whole design feels cheap, it doesn't shout professionalism. That's just my personal opinion though. Keep it simple. A lot of the time, a simple business card shows the most professionalism and class. My business cards are just white, with my name phone number and website right in the center with a bold, easy to read font. Not a lot of information, but enough to get people interested in my website. That's what you want.
i agree w/ the ^ font comments. Clean it up a bit man and what allen said, white space isnt a bad thing. Another thing to keep in mind is printing. I'm not sure if you'll be printing these, or getting them professionally done, but unless you're printing on a black card (which wouldnt come out that good on a home printer) you're going to use a lot of black ink.
Drop the scripty font and go for something easier to read for the phone number and email address. Maybe do the logo in the background in a solid dark grey instead of a glow, these things never print out the way you'd expect.