I use (the) awesome window manager. If you haven’t heard of it, you are missing a great window manager. It can deal with tiling and floating windows, is very customizable and is the best wm I’ve tried (over openbox, fluxbox, xfce, gnome’s, enlightenment, etc.) Go to it’s website to learn more.
This post is because I’ve been trying it’s support for multiple displays and is great!, Right now I have my laptop and monitor working together in a down-up configuration, and awesome have keybindings for handling the different displays. Absolutely great.
If you are a keyboard freak like me you will enjoy it!!