OK it's been a while, i Just want to see if there is a new way to jailbreak with my phone...anyone who can point me to a link here or flat out tell me it's not possible, would be a great help!!

I have a 3g(s) I am running 3.1.3 firmware 05.12.01 with model MB715..

it's currently jail broken with spirit!!

I am running window 7

i want to upgrade to ios4, is it possible?