Many users of Logitech Keyboard/Mouse combos are familiar with the "warp speed cursor" bug in the Logitech Control Center that has been around since Mac OS X 10.3.6. This bug causes the mouse speed to start absurdly high whenever the Mac is rebooted. It can easily be fixed by opening System Preferences, going to the Mouse pane, and clicking the mouse speed slider, but this quickly becomes tedious.
After Logitech spent several months ignoring my support queries, I wrote this AppleScript as a workaround. I saved this script as an application and added it to Login Items under the Accounts preference pane. Now whenever I log in, the mouse speed is automatically reset to a "normal" value. This script requires that you enable "Support for Assitive Devices" in Universal Access, and will prompt you the first time to do so if it is not enabled. Note that you can change the 6.0 value in the script to any number between 1.0 (slow) and 10.0 (fast) to suit your liking.
Many people have recommended using USB Overdrive instead of the Logitech Control Center, however, USB Overdrive does not support the extended keyboard functions. Those of us with Logitech keyboards as well as mice are stuck with the LCC.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050629045425132