Go bikes!! Listen to your callers and your guest, Dan–licensing is a terrible idea, and completely unenforceable. It would add tremendous costs to the system while doing little to prevent the tiny fraction of accidents that may actually be caused by cyclists. Most accidents are caused by drivers–and cyclists have a heck of a lot more to lose in this equation. What we need is more education for all drivers on the benefits of bicycling, and how to safely share the road. It’s not that hard!