As I was mentioning yesterday, The iPhone Dev Team had just released their new Pwnage Tool 4.0 to JB the new iOS 4. But hold your horses you JB'ers! It's not everyone are able to use that tool yet. Please read what The Dev Team had to say about he new Pwnage 4.0 before you proceed. The new Pwnage 4.0 Tool will for MAC will enable iPhone 3G, 3GS (old bootrom) to update iOS 4 and jailbreaking it.
iPod Touch - not supported
iPod Touch 3G - not supported