okey.
- Either extend the header image or center the whole thing.
- Also make it a jpeg or png, gif compression looks out of place, since it seems you're not going for that worn/retro/gif-y type of look.
- I'm not too keen on the squares, they kind of look dated.
- I don't like the grey text on the nav hover.
- Yeah, choose another font for sIFr or try making it bigger.
- You need more content on the home page, now it just looks empty.
- Put some color on your links.
- I agree with adras on the portfolio layout
- The code looks nice.
On a side note, it's your personal site. Why don't you show what you really can do? Why make it so standard and kind of dull? Don't get me wrong, it looks okey, but you're not a recycling/mountain-hiking/flower-picking company...