I was deploying a package via SMS earlier this morning. I had only sent the package out to a small number of machines (as a test) for a particular WinXP Hotfix (KB912919). The test group included everyone in my office, including my boss. Here's where the fun starts...
In a rush to get the package deployed I had forgotten to suppress reboots upon package execution. In short - I forced every machine in my office (only 12 or so machines) to reboot unwillingly, whether or not the user had any unsaved or open programs/files. Oops

Conversation with the boss went something like this:
Me: Hey boss, has your machine rebooted yet?
Boss: Why no, why do you ask?
(Boss turns around just in time to watch his machine reboot)
Me: No reason
(Runs out of room, laughing uncontrollably)
That is all, enjoy!