What you need to do for Jailbreaking Iphone OS 3.0.1 is:

1. Have a copy of 3.0 firmware downloaded on your pc for your device (I bet you do already because of 3.0 jailbreak)
2. Connect your jailbroken device iTunes and update to 3.0.1
3. Launch Redsn0w and choose the 3.0 firmware for jailbreak instead of 3.0.1
4. Follow the Redsn0w steps normally.

Well it works because nothing changed from OS 3.0 except the SMS patch, but can cause trouble in the future so I suggest you guys should (and that is what I am going to do) wait for an official Redsn0w release for 3.0.1 from dev team or an announcement at least to go on. Although they say no difference in the OS  (Yeah we need to download whole OS just to fix something, how lame is that!) I don't trust them because Appletards wants to make jailbreaking illegal and impossible with 3.x firmware releases. and Dev Team announced the same thing adding that you can Jailbreak with this method safely.

Unlocking Iphone is still same steps I described and via ultrasn0w. Works with 3GS also.