Back up your iPhone SHSH 3G/3GS/4 for iOS 4.1 with TinyUmbrella
Click the link below to learn more about the topic in this thread:
https://ccm.net/faq/10626-back-up-your-iphone-shsh-3g-3gs-4-for-ios-4-1-with-tinyumbrella
https://ccm.net/faq/10626-back-up-your-iphone-shsh-3g-3gs-4-for-ios-4-1-with-tinyumbrella