I've never used the "k". This offends the people who hung out at the local Witchcraft store. It just struck me as...silly.
When I last got in a heated discussion (and I use the term loosely) about it they came up to me and said "Well it's the only way to distinguish between stage magic and real magick."
To which I offended the playgans and fluffy bunnies by saying "Really Captain Obvious? And calling stage magic "Stage" magic is not enough to separate them?"
Got rather huffy about that. Wonder why.
But in all seriousness, I do not "K" the word because the average person knows bloody well that when I talk about the "magic" of Harry Blackstone, Chris Angel, Mike Rose (The Magic Kinda Guy from the Maryland Ren Fest
http://www.mikerosemagic.com/) and the others that I mean the stage illusions. Hell most of them no longer refer to themselves as "magicians" but "illusionists" since they work with optical illusions and stage trickery to give the (dare I say it?) illusion of magic.
And even if they didn't, odds are that they are not pagans and so would not see the other side of the coin of "real" magic.
Pagans and other actual magic users (gawd that makes it sound like I'm talking about Dungeons and Dragons dunnit?) *should* know by the simple fact that they frequently use real magic (either spells or ritual) and should bloody well know the difference between someone casting a healing spell and some schmuck on a Vegas Stage pulling a bunny out of his arse.
So no "K" for me. Magic is magic. What they do on a stage is a fascinating display of skill and slight of hand.