could you go to one of the iphones, tether the 3G using bluetooth to another iphone. Then use that internet on another iphone and jailbreak it. Then get MyWi and use it to jailbreak all the other devices. You could also make some email account(like firstname.lastname@example.org or something not your real email) then email yourself(on that account) every jailbreak pdf. Then set up that email account on a sample iphone. Then jailbreak it, then get MyWi to tether to jailbreak other devices.