How do I rekindle a relationship?

My boyfriend and I are both seniors in highschool and we have been dating for about 6 months. Everything has been really great and we really haven't had any problems. But lately, it just seems as if we don't have much to talk about and the "spark" has gone. We both really like each other, we just seem to be falling out of love, if you know what I mean. Is there a way we can work this out, or does this just mean that the relationship is over?