Lights: knuckle light for really dark runs. Assorted blinkies front and back for the benefit of traffic.
Belts: Nathan water belt with 16oz bottle and pocket for long runs. SPIBelt for shorter runs. Useful for blinkies.
Sweat protection: Halo headbands and caps. The gutter keeps the sweat out of your eyes = no sting! I have five of these that I rotate through.
Cold weather under layer: under armour cold.
Really cold weather: skiing underwear. Yes, you can run in it!
Shoes: Brooks Beast. Awesome shoes. Heavy but very very stable. Rare to find on sale. Buy half a size larger than normal shoes. I also use Brooks Adreneline shoes now too. Slightly less correction but still a very stable platform and a few ounces lighter. I did find that my big toe wore through the top of the toe box and I ended up with duct tape on the front for 300 miles.
Apps: General running with Mapmyrun that ties into the Vitality programme offered by my company and earns me points that can be exchanged for Amazon gift cards! Nike+ for step counting and non-GPS measurement of routes, plus shoe distance tracking. Tap-a-lap for track runs.
Gadgets: Nike+ shoe dongle/sensor used by the nike+ app that is built into the iOS of my iPhone. Mapmyrun Bluetooth heart rate monitor to track heart rate zones.
Tech Platforms: Apple iPhone 5.