Apple's iOS 4 looks great, has loads of new features, works just fine on a 3GS. But it's turned our iPhone 3Gs into expensive ornaments: it made them - and the 3Gs of everyone we know - so slow they were barely useable.
The good news is that you can fix it; the bad news is that you need to dump iOS 4 and it takes ages. Here's how to roll back iPhone OS to 3.13.
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