Endorsed by no other than pro skateboarders Rob Dyrdek and Paul Rodriguez, the Silver Truck company is known for the quality of its trucks (skateboarding trucks it is). They came out with this multi-functional tool for your skateboard. No need to carry several tools anymore, the Silver Skateboarding Tool ($18) does it all. Everything you need to assemble or maintain a skateboard is there such as a hardware ratchet, a slide out screwdriver, a detachable allen key and a precision file.
Here is pro skater Josh Kalis showing how to use the Silver Multi-Functional Skateboarding Tool: