In addition of my previous post about Fix iPhone OS 3.0 SMS Vulnerability With iPhone 3.0.1, therefore, all iPhone 3.0 users are advised to upgrade to iPhone 3.0.1, but the question now is iPhone 3.0.1 jailbreakable and can unlocked? Yes as dev team has assured that redsn0w and ultrasn0w can be used to jailbreak and unlock iPhone 3.0.1:

What you need to do now is doing some trick in redsn0w. Nothing to worry about, just upgrade to iPhone 3.0.1 and jailbreak it!
