Hi EP,
To be honest, I was surprised I got into USC. My GPA is just shy of 3.0, and I performed sub-par on the GRE's (480 Verbal, 650 Quantitative). The U.S. News & World Report issue on Best Graduate Schools listed USC's Viterbi School of Engineering as #7 and #4 among private universities. The average quantitative score was 754 and the acceptance rate was 49%.
What I believe got me into the school was:
1. undergraduate research experience - I worked in two different physics fields for approximately 1 year each, gaining valuable experience with regard to lab procedures, experiments, reading/writing reports, and working with electronics/systems. This is definitely a plus when pursuing an applied scientific field such as engineering.
2. Working for a professor in the lab gives you immense leverage when looking for letters of recommendation. Make sure you approach the professor early in the semester, as they are very busy and it will take them a few months to piece together a good, meaningful recommendation. Be sure to provide stamped, addressed envelopes too. Check back later in the semester to see where they are in the writing process.
3. The statement of purpose is probably the most important part of the application. Departments are looking for someone who is enthusiastic, knows what they want to do, and fits in with their own research goals. I know I was interested in space systems design so I focused the letter on my interest in Dr Gruntman's research and referenced one of his papers, showing that I truly had an interest in his field (also a little brown-nosing too, but hey). Even if you don't know yet what you want to specifically study (which you probably should if you plan on going to grad school) be sure to state broadly your plans for the future to show that you have a direction you plan to go in rather than going in blind.
Overall, I believe that the three things above gave me a big boost in the competition for a spot in the school, and also helped to compensate for my other sub-par qualities (such as GPA and GRE's).
Hope this helps. Let me know if you have any more questions.P.S. Does anyone have a response to my orignial question? Thanks!