Combine orange juice, lime juice, garlic, cilantro, salt, cumin, oregano and crushed red pepper in a large ziplock bag. Add steak, seal bag and turn to coat with marinade. Let stand at room temperature for 15 minutes.
Preheat a gas grill to high. Oil grill. Remove steak from bag, discarding excess marinade. Grill steak to desired doneness, about 2 minutes per side for medium-rare. Transfer steak to a cutting board and allow to stand for 5 minutes before slicing and serving.
This was pretty good. I thought it could have marinated a little longer. If I make this again I will probably marinate it for a couple more hours. It was very easy to make though and if marinated a little longer it would have been bursting with flavor.