Big vein

[pedro_pedro]

Thats mine. It is also not a huge vain, but its ok

http://www.lpsg.org/members/pedro_pedro/albums/little+part/548042-dscn1636.html

 

[buffbaldy]

my big vein runs down the right side of my cock

 

[B_Marius567]

I was made fun of for having a big vein on top of my penis and people will ask me if a bug bit my penis.

my twin has no veins showing and i have veins poping out all over.

 

[DannonCannon]

Yup, I've got one too. It does a u-turn and ends right at the circumcision line. Maybe that's why the OP associated it with circumcision.

Girth Brooks has a nice vein on the top of his dong, too (fourth pic down)...