Chess tournaments are all day affairs: 5 rounds, no elimination, and about an hour to an hour and a half each round. So the wise parent brings something to do. I usually bring books to read. I am bringing:
Jonathan Strange and Mr. Norrell (dang, this book is dragging for me)
Beyond Belief: The Secret Gospel of Thomas
It's on the Tip of my Tongue (Word Retrieval strategies)
An Alfred Hitchcock Magazine
It's always good to have a variety, because you never know what you will be in the mood for, and you will probably want to switch around. Of course, I may find some nice chess parent to talk to and not read at all.