Apple has just rolled out iOS 4.0.2 for public download. You can update to iOS 4.0.2 by connecting iPhone with iTunes. Direct download links for iOS 4.0.2 will be posted here soon, stay tuned. iOS 4.0.2 update includes the fix for PDF exploit used in JailbreakMe tool. So, if you are on jailbroken iPhone, you’d rather stay away from this update.

iOS 4.0.2