(this may double post)
Munchkins are like profanity. You'll know 'em when you see 'em.
I live in a dorm, and there is a ranging munchkin infestation downstairs. I was talking with my roomate yesterday (who does not play RPGs, but does like RPG computer games), and he told me what he heard the ppl downstairs had in their game.
Apparently, a girl in this group is playing a Half-Dragon/Half-Elf, Ranger that has six diffrent min-maxed magical scimitars and uses quickdraw feat so she can perform any attack with any scimitar. Oh, and being as a half-dragon, half-elf, dual weilding six diffrent min-maxed magical scimitars wasn't enough, they invented a new feat for her, that lets her make a dex check in order to perform extra attacks, so she keeps attacking until she fails a dex check.
I also had one of the ppl in this group try and explain to me his minotaur that was blessed by the gods and is dual weilding +6 vorpal greatswords of returning, yes, they have returning because he apparently uses his pair of +6 vorpal greatswords as THROWING weapons.
Their gaming sessions are pretty much all about the DM opening the monster manual, and having some totally undefeatable monster appears that is unkillable until the DM gets board with lording his monsters invulnerability over the players, and has it simply fall over dead, only to have a magic portal open up and have another totally undefeatable monster walk in.
That is NOT 'kick in the door' power-playing. That is munchkinism.
Personally, I got bored with that kind of entertainment some time between pre-school and kindergarden.