It is not a secret that US schools, institutions, and industries have always tried to attract the best and brightest students, scholars, and scientists from all over the world. In fact, the ability to continuously attract such persons plays a vital role in the prestigue of many institutions. In physics alone, for example, slightly more than half of the graduate student population in US universities are international students. However, these numbers a slowly declining after 9/11. The major reason attributed to this decline is the increasing and lengthy problems in obtaining an entry visa into the US to either study, or work. While the problem currently isn't as severe as it was the first two years after 9/11, there are still cases where students and scholars did not receive visas on time to attend classes or conferences. If you intend to study in the US, or pursue your postdoctoral work here, I strongly recommend you read the article in this month's issue of Physics Today. http://www.aip.org/pt/vol-58/iss-2/p49.html Pay attention to two particular points: 1. Most fields of physics appear on the State Department's Technological Alert List. What this means is that if you are going to be, or already majoring, in physics in a particular field, the nature of your research will require that you undergo a "visa mantis". This is roughly a review of that field and whether it is "appropriate" for you to be doing it. This applies especially to postdoctoral scholars, since you are now considered to be an expert in that field of study. So there is a good chance that your application for an entry visa will NOT be approved of immediately (expect a 2 to 4 week delay). 2. The US National Academy of Sciences is keeping track of those who, for some reason, have their visa delayed for more than a month. Take note of the link given in that article where, if you are in this predicament, you should fill out that questionnaire. While this does not guarantee that you visa will be approved, at the very least, it will make sure that your application isn't lost or ignored. The best advice out of all this is to apply as early as possible. If you are applying for a new entry visa, start 6 months ahead of time, and certainly as soon as you have received the appropriate visa from the relevant institution. If you leave the US for a vacation or any other reason with an expired entry visa, make backup plans if you are delayed (plan on a delay of 2 to 4 weeks after your initial application). Things are improving, but they're improving slowly. Now, all of the above may or may not apply to those who are citizens of what the State Department categorize as "sensitive" countries. If you are from China, India, Russia, etc., expect even longer delays and possible additional background checks. Consider the above as an unofficial advice. You should always check the State Department's website, and the relevant US embassy's website on the exact info at any given time, since these things are continually in flux. Zz.