Immigrant entrepreneurs founded 25.3% of the tech startups in the past decade. And foreign nationals living in the United States were responsible for about 24% of international patent applications in 2006. This information is from a study done by Duke University, available in PDF here.

* There was at least one immigrant key founder in 25.3% of
engineering and technology companies founded between 1995 and 2005.
* Together this pool of immigrant-founded companies was responsible for generating an estimated $52 billion in 2005 sales and creating just under 450,000 jobs as of 2005.
. . .
* Foreign nationals residing in the United States were named as inventors or co-inventors in 24.2% of international patent applications in 2006.
* This percentage increased dramatically from 7.3% in 1998. This count does not include immigrants who became U.S. citizens before filing a patent application.

The people who are attacking immigrants in the media ignore and forget the huge contribution they make the the US economy.
The state of Texas has documented the financial cost and contribution of undocumented immigrants in a report. The undocumented contributed $17.7 billion to the state economy, and $1.58 billion to actual state revenues. In summary the report says:

The absence of the estimated 1.4 million undocumented immigrants in Texas in fiscal 2005 would have been a loss to our gross state product of $17.7 billion. Undocumented immigrants produced $1.58 billion in state revenues, which exceeded the $1.16 billion in state services they received. However, local governments bore the burden of $1.44 billion in uncompensated health care costs and local law enforcement costs not paid for by the state. Carole Keeton Strayhorn, Texas Comptroller

And, illegal immigrants are bolstering Social Security with billions.