BERKELEY – Sergey Brin, cofounder of Google, showed up for class at Berkeley this week, a surprise guest speaker in SIMS Associate Professor Marti Hearst's "Search Engines: Technology, Society, and Business" classroom Monday afternoon. Casual and relaxed, Brin talked about how Google came to be, answered students' questions, and showed that someone worth $11 billion (give or take a billion) still can be comfortable in an old pair of blue jeans.