In Kubuntu or KDE (I think...at least with Beryl), a window can get positioned so that you can't grab the title bar (the bar up top that has the menus on the left and right). To move it, hold down ALT and click anywhere on the window and drag.
Shading a window will collapse it into the title bar. To do this, double click on the title bar on top. You will be able to fit a ton of windows on a desktop and not have to go to the task bar, or use the ALT + TAB combination to cycle them. Simply double click them to "unshade??" them.