GreenPois0n RC5 tool has been updated to beta 4 and is now available to download for both Mac OS X and Windows. GreenPois0n RC5.4 could be used to jailbreak the newly released Verizon iPhone 4 which is on iOS 4.2.6 firmware. The tool is pretty easy to use and takes only little time to do the jailbreak process like the previous versions of GreenPois0n.
Download GreenPois0n RC5.4 (beta 4) from here