You might want to check with universities with departments in your field. Where specifically are you looking?

There are also program that sets up international internships, from visa, to housing, to airfare:

Alliances Abroad (http://www.allianceabroad.com/): offers a program called Career Escape with trainee program in the US. This program is open to university students and recent graduates who want to train in their professional field to gain valuable international experience. Paid positions are available in many fields.
InternAbroad (http://www.internabroad.com): this is a service from GoAbroad.com that provides offers for internship and work abroad.
InternshipsAbroad (http://www.internshipsabroad.com): offers internship opportunities mostly in America.
http://www.aipt.org,
http://www.internjobs.com,
http://www.volunteerabroad.com/listingsp3.cfm

CCUSA (http://www.ccusa.com) requires you to hold a J1 visa. They offer practical training in the United States (maximum is 12-month work placement). Applicants are responsible for finding an employer to offer a training program in one of the approved categories. Once a company is located and the information given to the local CCUSA office in your country,
You are responsible for all flight and travel costs to the USA and all accommodation and living expenses during your stay.


Good luck!

 

Unfortunately many of these programs are not free. They arrange for the trip as well as the internship, but at a price. Arranging visas, etc is difficult and many companies hesitate at hiring from abroad.

You can research listings on your own at sites like monster.com or directly with institutes that offer what you are interested in. Do some research int eh area you are looking and find companies you would like to work for, then send them a letter of intent with your resume.

Best of luck!