What is the best (cheap but comfortable) way to travel from Paris to Barcelona?

My girlfriend and I are traveling from Paris to Barcelona this November and we’re wondering what method of travel would be best under our circumstances (just graduated, on a budget, want a cheap but reasonably comfortable ride)

What is it about Paris Hilton that makes her so loved and admired around the world?

Our teenage boys want a girlfriend like her, teenage girls want to be like her, everybody likes her… My great grandma knows who Paris Hilton is and she is in coma… How do you explain this?

Where should I go for Gluten Free food in Paris?

My girlfriend has celiac disease (an allergy to wheat, flour, etc) and thus cannot eat pasta, bread, and many other common foods. Can anyone suggest restaurants with gluten-free options or health food stores where she can buy food while we are in Paris?