What's something you never leave home without?

My wallet and my cell phone. It's amazing that I lived for 40+ years without a cell phone. Now, I can't live without it. I feel naked.

My purse and a book.

My phone, my plastic and a bottle of water.

My wallet, cell phone and pocket knife.

I have pondered your question and in reality the only thing I can think of that I have never forgotten are my shoes.  Yes I even got into the car and drove to the mall, parked and realized when I felt the cold air I had no pants on. Yes I went home.

My phone.

Its part of a "Phone Wallet" that has my plastic in it.

My purse.

My wallet cell phone

My camera and a phone

Phone. I feel naked without it.

Never, ever?

My house keys.

My feet.

My sense of humor.

My glasses.  Without them the world looks like a Monet painting. 

I never leave home without my water bottle and my phone. However,
if I have to choose only one of them, I will take the latter. This is because I
can purchase something to drink in a shop, but I cannot access the contacts
stored in my phone from anywhere else. ;-) Additionally, it will prevent me
from getting lost as I can connect to the GPS.

my cell phone.