[quoteA mate can only teach you so much, but an instructor can tell you all you need to know... and THEN you just rely on your mates for tips...

Yeah I dunno about this. I have lost a bit of faith in the IKO thing recently after seeing people get their IKO 'badges' when they could only just go upwind and could not even jump yet. They were then put on a sort of probabtion where they have to come up to speed in three months or something like that, but up to speed did not include a range of wind conditions, (just benign, smooth 12 knots and flat water) or even tricks - just jumping. Seems a bit dodge to me. I guess when you pay over a grand to go on the course, you want something out of it..
And I think it is fine to get your friends to teach you as long as they are really good, experienced riders, but you just gotta be sure they are (and some of these people will be IKO qualified - I see Dan Anderson on the list above, (the only one I know) and I know he is very experienced).
IKO gives the impression that they are totally safe, and if you follow their instructions you will be all good. This would mean that no IKO instructord have ever been killed kitesurfing, but this is not the case - I've heard of 3 just in the time I have been doing it. And I saw 2 guys, both (overseas) instructors, nearly get killed ON THE SAME DAY by doing things i would not have done - and I was pretty much a beginner then. But they were wearing safety orange....the universal colour of good judgement.
I'm a bit over all this IKO stuff, I can see that it serves a purpose, and if it was given out to consistently good people, sure, good plan, but at the moment it looks a bit like a cartel than anything. There is a need for it- no doubt about that, in that you can find people to teach you in a wide range of places, instead of taking your chances if you don't really know anyone to teach you, (anyone who is any good that is). But the IKO is not the be all and end all. Some are fantastic - really experienced and trustworthy (maybe most in Australia), but some are rough as. You should never sign away your critical faculties in favour of an IKO instruction - this is a dangerous sport. I guess it's like everything -buyer beware. And yeah, the guy on the beach should have listened to the kiter who knew what he was doing.
And another thing - back in the old days when my husband was learning, there was no IKO - they all taught each other, and there were a lot of them too. And it all seemed to go okay - a few scratches and a bit of swearing, but generally good.
I'm sure this might cause a ****fight, but it's just my 2 cents worth.