Do you have an iPhone 3GS, and are wondering what improvements the much vaunted new iPhone OS 4.0 will bring to your phone?

Well, as you might know, that is not possible right now, as the iPhone OS 4.0 beta has so far only been jailbroken for the iPhone 3G, with the redsn0w 0.9.5 jailbreak tool. But, do not despair, as hope is here in the form of a new jailbreak method, introduced by kaatjeNL (an ex-apple employee). The beauty of this jailbreak is that it doesn’t upgrade your baseband, so you can enjoy all the jailbroken goodness of the new iphone OS 4.0 Beta on your older baseband, using ultrasn0w unlock.

This nifty hack has been achieved by patching up the firmware in several places, then allowing a custom firmware (like the PwnageTool and sn0wbreeze) to restore it using iTunes on the iPhone 3GS, keeping the older baseband unlock intact.

While there is no release date for this tool, and by the author’s own admission (see method link), it is very much a work in progress; it is expected to debut with the next version of the PwnageTool, which will jailbreak the final release of the iPhone OS 4.

The iPhone OS 4 support will extend to all iDevices that run on iPhone OS, once it is officially released at the WWDC, so this method can prove to be a godsend for the early birds who want to get a taste for the functionality of the new OS, when unshackled from the grips of apple copy protection, and maybe get a head start on developing new multithreaded apps for the new iphone OS.