I've seen them before, I just don't know what they are...

I found a couple of these crawling around on the shore of the Gulf of Mexico earlier. I've seen them on South Padre Island too, and they seem like friendly enough little creatures, I'm just not sure who they really are. Are they a type of little isopod or something? Does anyone know their common name or scientific name? If so, help a brother out and let me know.