From The New York Times' Economix blog:

Do you agree with David Bier from the Competitive Enterprise Institute that “highly skilled foreign workers do not ‘take jobs’ — they make jobs” and that the hiring of foreign workers makes the economy more efficient and actually increases opportunities for American workers?
— rational expectations, Westchester, N.Y.

Our report did not look specifically at the impact of high-skilled foreign workers on employment, so we will defer to the work of others in this answer.