The jailbreak community has been active lately. Thanks to a surprise release of the limera1n jailbreak tool from Geohot, the release of Greenpois0n was delayed. Now both hacks use the same unpatchable bootrom exploit and are available to the iOS device-owning public.
Greenpois0n is also still under beta development. Right now it works for the iOS devices listed above but only when running iOS 4.1. Both Windows and Linux versions are available at greenpois0n.com. The Chronic Dev Team announced that support for Apple TV and iPod touch 2G jailbreaks are in the works, as well as a Mac version.
A wireless carrier unlock that will allow your locked iPhone to work with any compatible service provider is still under development. In the meantime, make sure to use TinyUmbrella to back up your SHSH files.
More explanation from the iPhone Dev-Team blog: “Because the ‘untethered’ part of this jailbreak comes from a userland hack from @comex, you should still backup your SHSH hashes for 4.1… This way you can always come back to an untethered, jailbreakable 4.1 on your devices after Apple has closed their 4.1 signing window (they’ll close the 4.1 window once they push out their next firmware version).”
As always, jailbreak tools for any and all iOS devices are released free of charge. There are many fake products that will scam users out of money. Never pay for a jailbreak tool unless you’re voluntarily donating to the developers!