On occasion I am asked what it takes to move to the United States if you are not a US citizen. Coincidentally, I was recently pointed to a 2008 issue of The Reason, which has a flow chart illustrating just how complicated legal immigration to the US is:
(click the image for a full-size PDF version)
Now, the flow chart somewhat presumptuously implies that every immigrant to any country wants to become a citizen of that very country, which I have found to be untrue -- some of my family's best friends have lived in Germany for decades and have no intention to give up the citizenship they were born with. But the chart still gives a helpful overview of just how hard it is to indeed go down that road if you wanted to. What might surprise some people is that US immigration law is among the strictest in the western world -- somewhat ironic, given its traditional status as an immigrant country.
Another thing that has caused confusion before: Just because you marry a US citizen, you don't automatically earn a residence permit (let alone citizenship) without any further ado. It makes it easier to achieve both of these things, but a US citizen's spouse still has to file a bunch of paperwork (and bring time and patience) to receive the necessary papers to enter the country.
Thanks for the link, Jabba!