I heard some people expressing the interest to increase the width of Community Server skins. I use the paperclip skin, so I wanted to modify that. Searched a bit and came across this post from Dennis van der Stelt. He explains in detail how to change it, and also have a .png file that you can download and use to modify the header. I couldn't change the header yet, so didn't apply the changes, but here is the css override that you need to apply:
#nav
{
width: 1092px;
}
#main
{
width: 834px;
}
#content
{
width: 1092px;
}
#masthead
{
background-image: url(/Themes/Blogs/paperclip/images/myimage.jpg);
width: 1104px;
}