http://jaxov.com/2011/02/unlock-for-iphone-4-02-10-04-03-10-01-04-10-01-baseband-coming-soon/ Coming soon.
Greenpoison? I only have an ipod touch, but it worked untethered for 4.2.1 edit: ah sry, though you mean jailbreak instead of unlock. this won't work.
you talking about jailbreaking? i already jailbreaked my iphone. i just need to unlock it but it's not available yet.