My first piece of advice is not to do it 3 hours before you need to leave for your flight, especially if it's a Sunday and an Easter Sunday at that. [What do you mean Capitol Hill Bikes doesn't open until noon? What do you mean Frager's is closed? Frager's should not be able to be closed. That's like the firestation being closed]. I almost didn't get the handlebars off.
I followed City Bikes instructions which were pretty good.
But from there SWA was pretty easy, even if they did charge me $50 for the oversized box, and it was the last piece of luggage of the plane. Skycap's are the way to go. The Yaris, btw, can carry you AND either another person or a bike in a box, but not both.
So far so good.
Update: Bicycling magazine has some info on traveling with a bike, including best and worst airlines.