I found this recipe on the daily dish site for No Salt Added Bagels.

It uses an ingredient/technique I don't think I've seen before. You take a peeled potato, slice it into thick slices, boil it for 15 minutes, then use a cup of the potato water in the recipe. (The recipe says you can either eat or throw away the potato, it isn't used in the recipe, just the potato water.)

I'm going to try this recipe soon, though the stuff you put on bagels tends to be pretty salty in its own right.