When shopping, I carry a Bausch and Lomb 7x Hastings Triplet.
However, at home, if I want a closer look, I prefer to use my ultra-budget macro lens. For those of you with a canon DSLR, the 35-80 mm EF lens (which can be had second-hand for ca. $30) can be turned into an macro lens by simply removing the front elements.
Here's an example of a Walking Liberty mint mark through the lens - apologies for the poor focus.
