What is the best way to set up Clippy on someone's computer?

Wait until the victim steps away from their desk, then run Clippy from a USB drive or pre-copied file. The one-minute delay gives you time to get back to your own desk and look innocent. For maximum impact, create a custom clippy.txt file with messages personalized to the victim -- mentioning their name, their projects, or inside jokes makes Clippy feel eerily aware.