H1B Visas

H1B visa is a visa allowing US firms to employ foreign workers with a high skill set into the US and actually allows the workers to live legally in the US for 3 years which is extendable.  The visa is only valid as long as the person is employed by the sponsor of the visa, usually the hiring company.  The industries with the highest H1B hiring rates tend to be related to IT work or computer sciences, with colleges being close behind.

One issue with H1B visas the article brought up is that regulations are now requiring the company to have at least 50% of their work force be locally hired.  This actually caused the Indian firm to expand rapidly in the US and actually have begun hiring more and more of the local work force instead of resorting to using primarily H1B visa workforce.
http://www.business-standard.com/india/news/indian-it-firms-stephiring-inus/462917/