As long as they were not coming for business (generally okay, there are a few types of business not allowed under the VWP, including journalism), seeking employment, planning to marry a US national & had a return ticket.
Holy crap - I got my birth cert in the mail today! Expedite, indeed! 25 hours after I faxed the request the mail carrier delivered it. On to the next step!
My wife just got hers a couple of weeks ago. All she had to do was take her birth certificate to the post office. They took the picture, she filled out the forms and everything was sent from there. She paid the extra fee for the 'rush' and got it in about 2 weeks.
They mail your birth certificate along with the form, but you get it back with your passport.
Since getting your passport seems to have been covered I will add a couple of tips for international travel that I have learned over the years.
1) Make several photocopies of you Driver's License, Passport, and Birth Certificate. Put these in various places in your luggage. I usually have a set in my carry on, one in each piece of checked luggage, and in my wallet. While these are not legally valid they will make your life much easier if your id gets lost or stolen. Always have your passport on you in an inside or front pocket (harder for pickpockets). Use the room safe to lock it and copies of your documents up.
2) Make sure to have copies of your prescriptions and notes from your doctor for any medication that you are taking. Keep all medicine in the original bottles. This helps should you lose your medication or if you get pulled out of the line at Customs for a search. Also make sure to bring your favorite over the counter medicine, soap, toothpaste, etc with you. Don't assume that you can get it when you are there if you need it.
3) You don't have to worry about this as much in Europe as other places but always be aware of your surroundings and try to notice anything odd (a guy leaving a big duffle in front of a restaurant for instance) Terrorism is global and it won't hurt you to be alert.
4) See if your company offers any additional services for overseas. Ours has a contract with a company called SOS International that offers medical, legal, armed protection, and emergency airlift services should they be needed.
Again I don't want to scare you and you are not going to places that I goto like Israel, Malaysia, South Korea etc that are high risk zones but we all want you to have fun and come back safe!!
Thanks, guys - Paperwork for the app is filled out and tomorrow I go to the courthouse to file. Work's been so busy I had to skip lunch 2 days straight (hungry...).