Comment 66 for bug 683170

I recently moved from Opensuse with KDE (opensuse user since 2002) to Ubuntu, and I must say, this is the thing that annoys me the most in Unity. I also feel it should be an option.
In KDE it is a tick-box. By default it shows everything, but you can set it to only show the windows in your current workspace.
This is great for separating different types of activities you are busy with.
KDE takes it one step further, and you can even define more activities, each with its own set of workspaces, where you can even set different backgrounds etc.
Other than this, I like Ubuntu a lot, and can see why it is so popular, so I will probably keep using it regardless.