So we all know what these guys are, well I'm sure you all think you know what these guys are. They are known by a variety of names including pill bugs, roly polies, potato bugs, and many others but less commonly by their actual name. They are woodlice. However despite their names they are not actually bugs, nor insects for that matter - they are crustaceans and thus more closely related to crabs than millipedes. While I can't say for certain it seems as though that these two guys belong to the genus Armadillidium in the family Armadillidiidae. Just skimming the internet it's likely that they are of the species A. vulgare which is the common woodlouse originating in Europe but has since spread to the Americas.
I collected these guys under a stone slab outside of Baker Tower, Cornell University, Ithaca, NY in early September 2010. And while I have given you a species name that is only temporary as I am completely unsure about that, however I'm fairly certain of the family. If you are looking for some more information about them you can find this Pill Bug science page enlightening about their habitat, life cycles, and reproduction or you can check out the A. vulgare page for more information about that particular species.