One of the best features of Mac OS X Server is the built-in blog and wiki services. While it is not the right solution for every type of environment, it is a very good medium for internally hosted user generated content. Especially if you are using Active Directory or Open Directory. One of the most common requests I get when setting up a blog and wiki server is to customize the portal so that it is branded to the organization that it’s being set up for. One of the easiest ways to do this is to just edit (or more likely replace) the banner-bg.png file located in /usr/share/collaboration/css/serverhome_static/img directory. There are…