A good trick for me during work is to keep oatmeal on hand. I typically just fill my coffee cup with oatmeal and water then microwave, hit it with honey/nuts/dried fruit depending. Eggs,chicken and fish are bought like nobodies business. I grab Salmon when on managers special as well!
Most of my rides, I find bananas just about the easiest thing to eat quick. I do end up stuffing them back in my jersey depending on the situation which can be messy.