So it turns out I'm not entirely helpless. When I got home from work this afternoon, the rabbit was still in the same place I left him, and he was still alive. He was showing some positive signs of life. Unfortunately I wasn't equipped to take care of him, and it was apparent his mother wasn't going to come for him either. So I finally got the number of a wildlife rehabilitation group that would take orphaned rabbits and I found someone who agreed to take him. I drove the little fellow to Cary where a nice lady named Joy took him. She said he had a chance. She planned to give him antibiotics and clean up his eye. She also said it was a positive sign that he was sitting up and moving around. So I feel much better now. At least he has a chance.