Might want to add all these to your little list then:
> UK (can force people to hand over passwords)
You are aware that most, if not all countries can force you to hand over your passport? If you are arrested and bailed the government don't really want you trying to flee the country. Even if you're not arrested many courts can compel you to surrender your passport (for example, in a child custody case). Some countries will also make you surrender your passport if you're entering certain disputed territories (Chinese citizens, for example, must give up their passport when entering Taiwan).
and Turkmenistan.
Things take time in that part of the world
It turns out that progressive Saudi Arabia was far more forward-thinking when it comes to the abolition of slavery than I had imagined, they abolished slavery in 1962 not 1965...
But to answer your question, A LOT: http://en.wikipedia.org/wiki/Abolition_of_slavery_timeline#1...
(But also, ahem...http://www.loc.gov/rr/program/bib/ourdocs/13thamendment.html)
All smart assery aside, even today you are in big trouble as a Filipino or Eastern European maid or nanny if you choose or are tricked into setting up shop in Saudi Arabia
...
[x] UK (can force people to hand over passwords)
[x] US (probability that they reject people at the border/airport for ridiculous reasons)
[x] Qatar (exit visa required)
[x] Saudi Arabia (exit visa required)
...
Even if I'm not sure if those exit visas also apply to short term visitors. Better safe than sorry.