I was just married last Saturday and I went to Edinburgh on Tuesday to the US Consulate to apply for my new passport. (Name change)
They have walk up service on Tues and Wednesday morning if you live in Scotland. You don't have to send it off to the consulate in London anymore but the website hasn't been updated yet to reflect that information.
Anyway, I received my new passport today. That is a 4 days turn around. I'm seriously impressed.