Window tiling is nice; automatically placing your windows to not overlap and maximally use screen space. Switching fully to tiling window managers is not always feasible. Whaw is a program I wrote to tile windows on your screen completely independently of your window manager. It plays nicely with anything from modern window managers to using no window manager at all, calculating the proper arrangement then sending commands to your manager to carry out the placement.
Get it at http://repetae.net/computer/whaw/