Ace iPhone hacker George Hotz, know as Geohot, is planning a release this week of new code that promises to let users run their iPhone on the GSM cellular network of their choice.

The new free code, due on 4 November, is dubbed Blacksn0w, and will offer a baseband unlock of the iPhone 3.1.2 OS version, and the  standard 05.11.07 cellular modem firmware, enabling the phone to run on other GSM carriers besides the "legal" one, AT&T. Hotz has posted a YouTube video, showing the program in effect resetting an iPhone to connect to T-Mobile’s network.

The new code will be part of Hotz’s Blackra1n utility, which lets users "jailbreak" all iPhones and iPod touch models (except for the 8GB iPhone 3G): jailbreaking lets users load their own software programs, bypassing the official distribution mechanism of the App Store. The RC2 update added support for iPod touch MC models.

But without being able to unlock the radio, jailbroken iPhones still connect only to the AT&T network. Blacksn0w eliminates that restriction.

In his blog, the 20 year old Hotz slams the other iPhone jailbreak sites as "scum" for "making money selling freeware." Hotz was with one of the hacker groups that developed unlocking code for the first iPhones. A second unlock program was created by a group called the iPhone Dev Team

"I'm not going to post all these scam sites here, as I don't want to give them the pagerank boost. Rather I'll give you a whitelist, two people make unlocks, me and the dev team," he writes. "Every iPhone unlock site you see out there is selling our stuff, repackaged in some form or another. Same goes for jailbreaks, although ih8sn0w and chronicdev are legit. Notice what all the legit ones have in common? They are free."