Cellphone: HTC One (Verizon)
With the One finally available on Verizon and my Thunderbolt growing slower and slower (taking almost a minute to actually make a call after the "call" button is pressed), I decided to bite the bullet and upgrade. Solid construction with a lightning-fast 1.7 Ghz Quad-Core processor, incredible battery life, and fantastic 1920 by 1080 screen.
Flashlight: Titanium Innovations IlluminaTi CA1 LED Flashlight
I'm a firm believer in carrying a small flashlight on your keychain, as it can be a lifesaver whenever light suddenly becomes a precious commodity (which can happen more often and unexpectedly that you'd think). This titanium LED light runs on a single AAA and has high and low settings.
Keychain: Pickpocket Alpha, by Pangea Designs
An elegant solution to keeping your keychain secure yet easily accessible, as well as keeping its contents both organized and separated.
Pen: PicoPen, by TEC Accessories
I always try to keep a pen at hand (even when paper or other writing surfaces may not be), and the most compact and efficient solution I've found is the PicoPen. It's the perfect size for my (admittedly small) hand, and fits well on a keychain. My only gripe is that the pen is attached by magnetic fastener, which can be a problem if you also keep sensitive electronics on your keychain, or if the notion of it sticking to other steel-based items on your chain irks you. Pairing it with the titanium Pickpocket mentioned above, however, solves both problems.
USB Flash Drive: SanDisk Cruzer Fit CZ33 32GB USB Flash Drive (SDCZ33-032G-B35)
Incredibly small and inexpensive, there's no reason not to keep vital files on a USB drive like this on your keychain as an extra layer of backup on top of whatever cloud service you might fancy. Having a USB drive handy for file transfers is another thing that, once you've gotten used to it, you may find that you can't live without.
Wallet: Big Skinny Taxicat (Olive Drab)
The one weakness of the Slimmy line of slim wallets by Koyono is that they don't have a coin pouch. The Taxicat by Big Skinny eliminates that weakness in a form factor that isn't that much thicker, thanks to its ultra-thin nylon construction.
Watch: Marathon TSAR (Tritium Search and Rescue) on U.S. Great Seal Bracelet
The newest of five watches that I use in rotation, this rugged diver watch fills in the rough-and-tumble role where its 300-meter water resistance, quartz accuracy, and always-illuminated tritium-marked dial and hands come in handy. Requisitioned for U.S. and Canadian government use, this watch is the true benchmark for military-spec timekeeping. The matching bracelet is sold separately, but it really makes the watch with its solid links and endlinks. The U.S. Great Seal version adds nice symmetry to the "U.S. Government" printed on the dial.