Today is National Bike to Work Day! Here's the marketing angle. If you are wondering whether you should do it, here's one columnist’s answers to every protest you're likely to raise. But I'll add another one (for New York bridge crossers): free breakfast. That's right. Transportation Alternatives is giving you coffee, fruit, bagels, and muffins (so I hear) at several bike-able points of entry to Manhattan. Now that's my idea of marketing.