I had a look at the link provided above. The tabs in the extensions dir I already know, but I really like what RT has and I have no idea how that could be achieved. I just thought this could be a 'module' or an easy script what could be added to any website. It doesn't look all that complicated ... : ) just for those who can't do it.
I wanted to use it for the Dimensions (light) template to be able to change between two different links.