My college grades were/are pretty good. I have just under a 3.9 GPA right now, never anything less than a 'B'. I think one thing that helped me was my research experience. I came up with a research idea, got funding, lab space, other people, etc. Engineering research is much different than physics research, but I would highly recommend you try to get a position working in some one's lab. IMO it shows drive and initiative and is a bullet point on your resume that high schoolers can't match. Even if you don't go to the academy, engineers and scientists need research experience coming out of school.