JiffyPopTart
Bree-Yark
A MECHANICAL pencil. No dark ages gaming for me. And also a D20 that flashes when you roll a 20 from Thinkgeek.com.
Tablet. But that is just for pdf copies of books. I don't feel like i need computer aid to run 5e unlike 3.x. Which is SWEET!
I try to limit the amount of stuff at the table - I've found a lot of apps and visual representations just slow things down. But I've found my Chromecast/laptop/TV combo exceptionally useful and efficient.
We game in the living room next to my 40" TV. Using Chromecast I can share the screen with the players (an HDMI cable would work but the cord would get in the way. I imagine there are a few other dongles that could get the same effect). I'm constantly googling images of monsters to give my players a visual aid. I also keep a notepad and record initiatives on the TV. This lets players know how soon they will have a turn. I also occasionally use it for world maps. I don't prepare any of the images ahead of time.
It works really well if you can quickly alt-tab between programs. Control+E is a shortcut for searching.