Niku--you're still well in time to file for 2007. You get an automatic extension until June 15...just write 'tax payer abroad' on the top of your 1040. I assume you would just be filing the foreign income exclusion (2555 EZ) and a 1040, so shouldn't be too complicated. I don't believe there is any rule that you have to submit in order (ie, you can't submit 2007, if you haven't submitted 2006), but I'm no expert, so hopefully if I'm wrong here, someone will correct me.
2006 will be more complicated, because of cashing out the 401K, and all, but as guya says, just request duplicates of your statements, and fill those out. You can find copies of the IRS forms for 2006 on the IRS website (http://www.irs.gov/formspubs/article/0,,id=98339,00.html
Not sure when you are going to the embassy with your daughter, but they do have an IRS branch there, where you can submit your forms (they will stamp them for you, so bring a copy to have stamped for your records), and they can offer some limited advice/help in filling out your taxes. So you might be able to kill 2 birds with one stone there. You can just walk in--don't need a special apointment to visit the IRS office.
I know that it is a requirement to have filed the past 3 years in order to start the US immigration progress, but I have never heard of anyone having any problems registering a birth/obtaining a US passport for a child, or being stopped at the airport for not filing taxes, so I wouldn't worry too much about that.