I know you are just concerned for your son's feelings, but AT THIS TIME, you don't need to worry about it. It will be years before he starts to notice and if you stop focusing on it, you will probably forget it, too. People often make comments about babies that they would never make in front of an older child, so hopefully such comments will lessen as he gets older. If they don't, come up with a few witty comebacks, like, "We think he will become a musician someday because he'll have a really good ear for music," or something like that. Seriously, though, the biggest thing for you right now is where you allow yourself to focus. If you spend any time looking at his ears, plotting ways to pay for the surgery, wondering how you can hide them with a hair style, ANYTHING along those lines, then you are focusing on them. Focus on something else or just decide that you aren't going to worry about it right now (remember, it will be a long time before he'll notice).
That being said...yes, there is a surgery where they cut out the excess cartilage so the ears can lay back. I knew a boy in middle school who had this done and unfortunately the keloid scars he developed over the incisions was probably worse than if he had just had protruding ears. As for your boy, it's an option, though, for HIM to decide upon LATER. He is way too little to be worrying about this now. They may lay back on their own and you will have wasted all that time worrying about it. Plus, you'll have to wait and see if HE has a problem with it. He may like them! Ha ha!
Kick back and enjoy your healthy baby!