The first thing my eye was fixed on was the top left. Why? The green stood out. The blue next to the green breaks the overall color scheme. Keep one or the other but not both. The header looks incomplete.
The rest of the page is ok, would remove the Imac, your gonna get hammered fot it if not by Apple thenby people reviewing here,so let me be the first.
Remember that a user reads a site like a book from top to bottom and from left to right.
Overall, I like the layout of the site. But the empty green space is an eyesore. Just looks like something is missing there. You might want to try putting some fancy flash animation there describing your services. Also the blue beneath the logo, "what the net can be" doesn't fit. Try a different color.