Overall, I think it looks pretty nice. Why the hosting ad at the top? The logo certainly can use some help, it is very boring and should stand out a little more in my opinion. You have no branding at the moment. I don't like the rather large gap between your content area and the right column . With that large banner I'd consider increasing your font size, things are not very proportioned very well as it is right now. The red links on the dark grey background are tough to read and don't look right.
Usually in a portfolio section you get a little bit of information about what you did for the client, also maybe a thumb or small image that will lead to a larger graphic so the user doesn't necessarily have to go to the client website. Your portfolio just shows a small graphic and takes your directly to the client site, I don't really like that.
Like I said, overall, looks pretty good, but can use some fine tuning.
