ThinkSwiss offers scholarships for research in Switzerland. Supports highly motivated U.S. undergrad & grad students (all fields) to do research at a public Swiss university or research institute for 2-3 months.
The REU program in Computational and Applied Math (including the NSF funded UCLA REU site in Mathematical Modeling) at UCLA provides funded 8 week summer research opportunities for students to work on frontier level problems in Applied Math.
Programs offered especially for students in the College of the University of Chicago to give them exposure to world-class economic research and access to top scholars.
The University of Texas at Austin's University Transportation Center Undergraduate Internship (UTC-UI) can help you in your decision and prepare you for admission to a graduate program