Apple’s iPhone OS 4.0 is close to revolutionary if not game-changing. Some of the new features being Multitasking (3GS only), iAds (ads with fluff!), Game Center (openfeint?). Watch iPhone 4.0 Keynote in HD quality here. Multitasking Jailbreak folks have been enjoying the much touted multitasking feature for years while Apple finally makes it official, their style….