I have interned at Yahoo! Research and Development for the summer of 2010 and have also completed a project on Cryptography in my Department.
At Yahoo, I worked with the Advertising Applications team on Enterprise Web Services - Yahoo's search advertising platform. I helped in automating more than 350 API's during this period, and fell in love with Perl during the period- specially Regular Expressions.
I have also worked on Cryptography on cryptanalyzing the Rabbit as a part of the eStream project - including applications of Linear and Differential Cryptanalysis.
I was recognized as a trainer and gave a talk on Cryptography at Yahoo!. Mail me for the documentation of that.