Easy packed lunches for eating on the run at uni?

I'm in my 2nd year at uni, and my timetable is pretty tight. i don't have time to sit and eat lunch, so i eat it on the run between lectures etc. hence microwaves and uni kitchens are out of the question. i only ever buy lunch occasionally as a treat, just to save money. What are some easy things that i can take to uni for lunch? I'm really over taking sandwiches and rolls... unless anyone has any new and fresh ideas on sandwich fillings. thanks!