GHacks.net posted a guide on how to enable and use tiling feature in KDE 4.5

You’ve probably seen the advertisements for Windows 7 and the tiling windows feature. Believe it or not the very first tiling window manager was Siemens’s RTL (created in 1988). After that came a UNIX version called tAP (The Andrew Project) for the X Windowing System. Fast-forward to now and Microsoft claims to have innovated a new feature. Soon after that KDE refines the same feature and ads it into 4.4. Of course 4.4 was still suffering from numerous bugs. Fast-forward a little bit further into now and you have 4.5 which squashes tons of bugs and offers an amazing desktop that includes a bug-free tiling experience!

  KDE 4.5 Window tiling