Where did the 'pwnage' or 'pwn' or (verb) 'to pwn' come from ?

The best place to look is here, http://knowyourmeme.com/memes/owned-pwned

Owned (below: Variations) is a “leetspeak” slang word, derived from the traditional meaning of the verb “own”, as meaning to appropriate or conquer to gain ownership. The term strongly implies domination, severe defeat, and/or humiliation of a rival. For instance, “I owned the network at MIT” indicates that the speaker had cracked the servers and had the same root-level privileges that the legitimate owner of the servers had. It is also now primarily used in the Internet gaming culture to taunt an opponent who has just been soundly defeated (e.g., “You just got pwned!”) and as popular slang, outside of the internet. It is partly synonymous with a high degree of fail, and while sometimes these terms have been used interchangeably, it is more proper to say that someone or something is “fail” if they have been “owned.”

Edit as per comments.

"P"wned
The “p” in “pwned” alteration within the computer community has been believed to have have originated from typing too fast on the standard English QWERTY keyboard, thus missing the “o” and typing “p” instead. It could also be thought to pay homage to early hackers who tampered with phone equipment rather than computers--and “pwn” may simply be following this trend. (e.g., phishing, phreaking) According to one definition in the UrbanDictionary, the term “pwn” dates back to the 1960s at M.I.T. It was used competitively by programmers working on chess AI. When one out programmed the others he would refer to himself as King and the others as pawns. It started being used on Fido Net across the BBS world before internet went public, although it was used on the internet between university’s at the time.