I keep an emergency kit in a backpack in my car. Among other things it contains a Leatherman Surge, a Leatherman bit kit and extender, duct tape, cable ties and a pry bar.

The car-specific kit (not in the backpack) contains Rescue Tape (http://www.rescuetape.com/), radiator leak stopper, a tire patch kit, an assortment of automotive fuses, and some heavy gauge wire. There's also a battery jumpstarter with a compressor. The spare tire compartment contains a jack, tire iron, spare tire and jumper cables.

My bike kit contains a Leatherman Sidekick, a set of Fix It Sticks (http://www.fixitsticks.com/), a spare tube, a tube patch kit, tire levers, an emergency tire boot, and a chain repair link. All of that fits in a small under-seat bike bag. Other than the spare tube it's a very small and light kit. I had three "saves" of members of my bike group last summer with this kit.

My laptop bag contains a (pre-2004) Wave, a silent ratcheting screwdriver with a large assortment of bits, a precision screwdriver with an assortment of bits, and some cable ties.

I have a separate Surge, bit kit and extender in a belt sheath with a flashlight that I'll throw in a bag or on my belt depending on where I'm going and what I'm up to. If I'm carrying lighter it will be a Wave with no sheath and no bit kit. I always have a PS4 (or a Style PS if I'm flying) on my keyring.