Corn chips and salsa.
Fruit. Sometimes dark chocolate covered dried fruit (or ginger).
I usually have frozen chickpeas and/or brown rice on hand: both are very good mixed with salsa also.
Lunch at work (where I have minimal time and am often working straight through) is generally hummus on wholewheat toast with a tomato or two. Maybe some cucumber or sprouts if I have them.
I generally have a can or two of soup and a can of chickpeas/baked beans on hand for really rushed weeknights.
I make extensive use of frozen vegetables during the week, so almost all my weeknight meals have minimal prep time and take no more time than 1/2 hour from opening the cupboard to sitting down to eat.