What are five topics you can talk about for 30 minutes with zero prep?

Mine:

1. Practical CSS Golfing
2. The Two Things You Need to Know to Photoshop
3. Exploiting Physics (in Super Smash Bros.)
4. Personal Finance: Doing All the Things I Don't
5. Why You Should Play Monopoly Deal, Even Just Once

What are five topics you can talk about for 30 minutes with zero prep?

1. Off-Piste snowboarding in the French alps
2. Conflicts and compatibilities in Israeli, Chinese, and American cultures
3. Seinfeld is a show about Talmud teachings
4. Competitive analysis of popular assault rifles
5. Heroes of Might and Magic III