Derives from the word Pecker, meaning a small penis.
A pecka is a person, usually "gay", hideously uncool and has a very small penis.
A pecker will usually do idiotic acts to look cool, in a sort of sicophantical(sp?) way.
Pecka saw its first major usage in an army barracks in Donnington, UK. The word was then popularised in Walsall by a guy called Dudek.