Best method of tracking general daily activities

Hey all

Im still fairly new to MFP but as Im starting to get the hang of the calorie counting and food intake Im realising I should have a better way of tracking my daily calorie burn from walking around, running up and down stairs at work (Im a high school teacher), house work and general errand running.

I used to do Weight Watchers and we had a pedometer - which I could never seem to get to work (ain't no technophobe here - just couldn't get the thing to track properly between active points and non active points). I don't do WW anymore as the point counting didn't suit me.

Anyway what Im trying to get at is I would like to get some sort of thingy to wear on my arm that will help me to see what good I am doing for myself while Im choosing the stairs and not the lift

What does everyone here use? Id be very interested to find out. Also apologies as I fear this topic has been raised many times!

Thank you for reading....:)