Everyone knows that Rabbi Akiva darshoned many laws from the crowns on the torah letters. Does anyone know these laws, were they lost, or is this just from a beautiful midrash and there really were no such laws ??

I. Some of these halachot do actually appear in the mishna, bryta and tosefta, in the name of Rabbi Akiva. II. Some of them were only drash, and not actual laws - "Drosh Vekabel Sachar" - learn and get the reward. Rabbi Ro'i Margalit