Other blogger thoughts and experiences:
http://www.bikingbis.com/blog/_archives/2010/5/21/4534071.html
http://www.bikejuju.com/2010/bike-to-work-day-in-seattle/
http://kentsbike.blogspot.com/2010/05/work-to-bike.html
http://bikehugger.com/2010/05/bike-to-work-2010-portland-sea.html
http://carfreedays.com/2010/05/21/the-bike-fairy-and-bike-to-school-month/
In Ballard and Fremont, bicycle traffic seemed thick around 8am.
As soon as I left the driveway, I saw another cyclist:

There was nearly a traffic jam on the trail:

The commute station was a traffic jam:

But BikeSport from Ballard provided mechanical support:

And we had a demo of how to haul a lot of cargo by bicycle:

Experienced cyclists show how to be visible:

The Fremont Commute Station at Nickerson and Fremont Ave was HUGE and packed:

It seemed like a good day despite the forecast of Thunderstorms and 90% chance of rain.