Header

Note: You need latest version of Firefox, Chrome or Safari to see this. I guess this would become one of the famous solution soon. Pure CSS Solution, no extra html code, just styling. Though the CSS3 standards are not implemented by all browsers some of the websites have already started using it. There are a lot of hacks for IE to make it read CSS3.

Method 1: Big background image
Method 2: Header, Body and Footer
Method 3: Header and Body
Method 4: Pure CSS3
Method 5: Pure CSS3 with Multi Background