Randy was Computer Science professor for virtual reality / computer visualization at Carnegie Mellon in Pittsburgh. I don't know much about his research, but people say he was a great lecturer and scientist.
He was diagnosed with terminal cancer 2007/2008 and had about six months of "quality lifetime" left. In these 6 months he held (at least) two great lectures about "Achieving your childhood dreams" and "Time Management". Randy died July 2008.
Both lectures on youtube are really inspiring in terms of leadership, dignity and dealing with terminal cancer.
More on Randy on:
http://en.wikipedia.org/wiki/Randy_Pausch
and his diary of his cancer:
http://www.cs.cmu.edu/~pausch/news/
Randy Pausch Last Lecture: Achieving Your Childhood Dreams
Randy Pausch Lecture: Time Management