What are good topics for a PhD in computational linguistics?

What are good topics for a PhD in computational linguistics?

> What are good ideas for a Master’s thesis in computational linguistics?

If you could break out characters in novels, and do any analysis on the relations between them, such as via dialog acts, that would be uber cool. Focus is good, I wouldn’t go too broadly into movies, yet. I would call this more corpus linguistics than computational linguistics though. Hit me up for more ideas if you like.