Windows Vista users can add Expose-like slickness to OS with the aid of a free utility called Switcher. Once installed, Switcher allows you to choose how your app windows should array themselves; it also lets you customize your window colors and configure your own keyboard shortcuts.
Note: This program is donationware. It is free to try, but the author accepts and encourages donations towards further development. This link takes you to the vendor's site, where you can download the latest version of the software.