What's always in your pockets?

I have recently seen  couple of bits about the EDC (every day carry) sub culture, be careful if you google it, you can quickly end up in websites based on "preppers" especially from USA. 
Basically it's what you have in your pockets every day and trying to rationalise why you carry what you do. 

It got me thinking about what would be useful to always have to hand when in the garden. I tend to carry a knife which I find very helpful, but other than that I tend to have to go to the shed and pick up the tools I want if I see something that needs doing. 

I'm interested to know, is there anything that when heading to the garden is there anything that you always pick up and stick in your pocket (or already have there) that you find invaluable when in the garden.