IOS 4, which was released on June 21 at the WWDC2010 conference on June 7, is now available for download for iPhone and iPod Touch. All you have to do is connect your iPhone to iTunes, check for updates with “Check for Update”, download and install the new software. Be you, make sure to take your backups. For more information about iOS 4, you can check out the article titled iPhone OS 4 with its old name. Due to lack of hardware, multitasking feature will not work on iPhone 3Gs. 3GS users will be able to take advantage of all iOS 4 features. There are those who can use the iOS 4 software with multitasking feature on iPhone 3G after the software is corrupted by jailbreak etc. methods. Even though they say there is not much difference, it is among the most talked about topics in forums, where battery life is reduced, overheating and causes many errors…