A compact multitool that you can clip onto a keyring. So cheap you can afford to get a set for all your keys.
Price: $8.50 | More information
A small, portable battery power pack that can help top up my smartphone to keep it going through the long days. While it might not be enough to completely recharge the battery in an iPhone, it's good enough for a few extra hours.
Not bad for a device that can slip discreetly into a pocket.
Price: $20 | More information
The Nitecore TIP has become my go-to flashlight for poking around inside things. It features a built-in lithium ion battery that can be recharged using a USB charger and a micro-USB cable and I have to admit that it works very well.
With the press of a button the Nitecore TIP can switch from a 240 lumen monster that has a 30-minute battery life, to a 1 lumen firefly that can last for 46 hours. The flashlight has a 1-year standby capacity which means it's great for storing in a toolbox.
Price: $30 | More information
I've had reservations about storing USB flash drives on my keys because most are plastiky and easily broken. Kingston's DataTraveler SE9 G2 seems to have what it takes to survive the challenge.
The meta construction means that while keys do give it a good scratching, the internals stay protected for a long time.
Price: $12 | More information
This is like carrying around a small toolbox with you everywhere you go. It contains everything from a strong pair of pliers to a saw, knife, and very functional screwdriver.
Price: $90 | More information
After having one too many pen decide it was going to release its schmoo all over my pocket, I switched to carrying one of these around with me. I have broken them a couple of times and the company has always fixed it for me, and I have lost a couple too, but overall this is a quality bit of kit.
Expensive for a pen, doubly so if you're careless and lose them, but still the best pen I've ever owned for durability and the ability to keep writing no matter what the conditions.
Price: $25 | More information
No point carrying around a battery pack to recharge a smartphone if you don't have a cable with you. My portable cables of choice are the Nomad Keys. There's one for the Apple Lightning port and a micro USB version for Android and other devices.
Price: $20 | More information
Stewart/Stand silver stainless steel trifold wallet block unauthorized transmission from RFID enabled credit cards & IDs.
Price: $78 | More information
Cheap earbuds that you can shove in a pocket. Cheap enough that you're not going to cry if you lose them, and no battery to go flat.
Price: $10 | More information
I pop one of these in my wallet so I have a basic set of tools with me whenever I don't want to be weighed down by a full-sized multitool.
While it can't cope with heavy duty work like a Leatherman can, this is up to the job of tackling a lot of daily tasks that require a knife, scissors, and such.
Price: $30 | More information
Not sure as to the availability of these in the US, but here in the UK you can get little vials filled with radioactive tritium that can glow for more than 10 years, with no batteries, recharging, or exposure to light required. Really handy for attaching to keyrings and tools you don't want to lose.
Price: $12 | More information