In Sweden the PhD thesis is defended after printing, and it's printed after being judged as "good enough" by the supervisor (and the professor responsible for the graduate education). The defense is an important ritual, but it's very rare that you don't pass at this stage. The worst that can happen is probably that I look stupid in front of a lot of important people -- but let's hope not.
Yesterday I got my printed thesis delivered. I then delivered the prescribed 80 copies to the University library and signed a paper to allow it to be electronically posted. This has to be done three weeks before the defense. If I want to I can also physically post the "nailing sheet" on the wall in the University building. This I will do on Monday, since I really like rituals (and also the idea that people who go to the building can see what's going on in research). This is where I use the nail. Then I will nail the whole book to the wall at the Ångström lab for everyone there to see, and give the traditional nailing party at my department.
Now I just hope that I have enough copies printed.