This is the Helm of Awe on my calf. The Vikings believed it provided them with protection. The symbol would be cut into lead and then thrust between one's eyebrows, Victory in battle or conflict was supposedly assured thereafter. The "helm of awe" came to be understood as a physical object, a helm worn upon the head, supposedly it would confer invincibility upon the wearer. I passed on the forehead thing.
Nice! First time I see the exact same design used as a tattoo, here is mine with unfinished printed circuit all around.
Bye
http://www.myupload.dk/v/c498n6.jpg