Apple how do I jailbreak 4.2.1 untethered?

[pikachu945]

I was wondering if I can jailbreak my ipod touch 4g 32 gb I have blobs saved for 4.2.1 and 4.3b2
I want a untethered jailbreak so i can shut off my ipod and still have the jailbreak

 

[Fudge]

If you don't have a Mac, you can't right now.

 

[pikachu945]

I have a laptop with mac osx on it
but I do not have blobs for 4.1

 

[metamaster]

You need 4.2b3 shsh blobs, a mac, the 4.2b3 ipsw (which can only be obtained if you are a developer) and Redsn0w 0.9.7b6.