Vara en korkad 08:a?

Du kanske redan hittat svaret på din fråga någon annanstans nu, men svarar i alla fall.
People use "08" to refer to people living in Stockholm. The phone / area code is 08. It may be used as an insult ("jävla 08:or!") but it is sometimes also used among young 08's themselves.
 

mila is right, another native Swedish speaker here.

I'm an old "08".. moved down to South Sweden when I was 6, and now I have a fluent South Swedish Accent :)