It depends on what exactly you mean as an expression of Jewishness. You can be Jewish and tell others about it, but you can also, and vice versa, be proud of your religion and demonstrate it to the world through clothing, accessories or jewelry. I know that many of my Jewish friends wear Maccabee Apparel brand clothes with pleasure. I also love some of the T-shirt prints and I think this is a good way to let the world know you are Jewish.