iPhone Dev-Team demonstrated SHAtter jailbreak on their Blog The last method of "escape from prison (jailbreakme) no longer exists, since Apple has closed a hole in Safari, which he used. Next gen exploit shatter, discovered by pod2g is reported to work on all iDevices including iPad.
Dev Team posted that they are working on a new jailbreak: "This is not a job for one night, so please be patient a little longer, until we announce the fruit of our labors." The new exploit is already integrated in the beta version of Pwnage Tool for testing. SHAtter immediately cope with the new iPod Touch 4G and allowed to flash custom firmware. Of course, the new jailbreak will work with a glass gadget, iPhone 4.