At bike races I normally try to make the rounds, see what people are up to, show them new tools and get inspiration for new products. Stu Thorne put a common rotor truing tool in my hand and asked me to make it out of aluminum.
Apparently traveling with the cyclocrossworld.com team for a decade he'd learned to travel light. A few samples later we've got a 44 gram rotor truing tool called the Stu Stick. So whether you want to slip it into your hydration pack for that enduro mountain bike ride or travel the world working with one of the staples of cross racing it's up to the task. You can even use it to crack open a beer after you're done with the days fun.