iRotate lets you rotate your screen

iRotate provides convenient access to the native rotation capabilities present in modern display drivers, via a popup menu accessible from the system tray or with wide hotkeys. It's no longer necessary to resort to bloated Windows hacks, additional software layers or phantom drivers to achieve content rotation.

iRotate is a very small (125Kb) freeware (non commercial) program that supports most of the display drivers such as ATI, nVidia, Intel, Matrox, S3, XGI and others. The program offers exceptional speed and efficiency, with minimal impact on system resources and supports multi-monitor enabled operating system from Windows 98 to Vista.

The following hotkeys are enabled by default: Ctrl+Alt+Up - rotate 0 degrees, Ctrl+Alt+Left - rotate 90 degrees, Ctrl+Alt+Down - rotate 180 degrees, and Ctrl+Alt+Right- rotate 270 degrees.The program can be downloaded from here