SecureGuard Hidden cameras and nanny cams are the most popular and of their proven effectiveness in identifying cruel nannies and babysitters. We have a wide variety of spy cameras, nanny cams, and phone recorders.
Spy Gear for Kids - invisible ink from lemon juice, finger prints from charcoal. We are going to take their finger prints to use in a matching game later in the evening. The Boy Scouts site had a great page for fingerprinting.