When sending your Pi away on outdoor missions, the two main concerns that need to be addressed are the supply of power and protection against moisture. A lithium polymer battery pack is a good choice for powering the Pi off-road. They are usually marketed as portable smartphone chargers, but as long as yours operates at 5V and provides one or more USB ports with around 1000mA of output, it should keep your Pi happy and running, usually for five to ten hours. If you need a USB hub for your peripherals, make sure it can be powered by one of the USB ports on the battery pack.

When it comes to housing your spy kit, there are no rules except one—moisture will spoil your fun. A plastic food container with a tight lid is a good start for housing. It'll have to be transparent plastic if you plan to include a webcam with the kit, obviously. You might also want to line the insides with something soft, such as bubble wrap, to make the ride less...