This series contains some outstanding interactive maps. This one will show you where foreign born people have settled through out the United States, and how that's changed over the last 100 years.
It also includes an ongoing debate called "do we need foreign technology workers?"
The most recent addition to the series follows Google's experience with how Tech Recruiting Clashes with Immigration Rules.
BTW -- an interesting Bill was just introduced in the House of Representatives. H.R. 1791 would:
amend the Immigration and Nationality Act to authorize certain aliens who have earned a Ph.D. degree from a United States institution of higher education in a field of science, technology, engineering, or mathematics to be admitted for permanent residence and to be exempted from the numerical limitations on H-1B nonimmigrants.Source:
GovTrack.us. H.R. 1791--111th Congress (2009): STAPLE Act, GovTrack.us (database of federal legislation) (accessed Apr 13, 2009)
