Here's a free Google Analytics dashboard to check how much the 'iOS 6 Search vs Direct' issue affects your site: (note: originally this covered just ios 6.0. I've updated it to cover all versions of ios 6)

It contains just 2 pie charts. One shows the 'search vs direct' mix for iOS 5, the other shows the 'search vs direct' mix for iOS 6. In theory, those pie charts should show very similar numbers. In reality, you'll see that in iOS 6, a lot of the 'organic' traffic seems to have moved over to 'none' (aka 'direct').

If you haven't come across this issue yet, in summary: Apple's iOS 6 update means that lots of Safari 'organic search' traffic is now being misread as being 'direct' traffic. If you're a search marketer, this means lots of your effort is going unmeasured. If you're a website owner, this means your 'search traffic' may be unexpectedly lower in Google Analytics (or any other analytics tool), and that this may be a measurement issue rather than reality.

I've included 3x anonymous examples of the impact this has had below. (note the orange 'direct' line rising & the blue 'organic' line dropping proportionally).

Again, the dashboard here will help you figure out if you're affected:

There are further details on the issue at SearchEngineLand:
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