Office Spying Kit.

From the website:

Your sleuthing gear includes a micro listening device for those not-to-be-missed conversations between bosses. You also get two discreet mirrors which can be used singularly or can be built into a simple periscope—essential for snooping over cubicle walls. And don't forget the two-in-one invisible ink pen and decoder that lets you record classified information without being discovered. In short order, you'll be the CEO—that's Chief Espionage Organizer-and hot on the trail of the latest office coup!

I wonder if the people in the HP spying brouhaha used this ...

Link - via Arbroath