3.0.1

Yea. You can use redsn0w to do it. Or if that fails I've seen already jailbroken firmware tahr you can download and restore into on thepiratebay.org. I've never tried that method though so be careful lol.

i tried jailbreaking my brand new iphone that was on 3.0.1 but i could not get it to go into dfu mode. ive jailbroken my ipodtouch 2g a few times and now how to put it in dfu mode but for some weird reason my iphone wouldnt go into dfu. it would cut off then flash but it would never go to the next step to start jailbreaking. after letting it sit for a few minutes with it doing nothing, i wound touch the power button and it would turn on, like all i did was put it in sleep mode.  i dont know if this is something new apple has done to keep you from jailbreaking, or maybe i just messed up somehow. but like i said, ive jailbroken my ipod a few times and know how to put it in dfu mode.

well why dont you make sure it works before you get everyone else to try it and get their hopes up... that would be a good idea dont you think?

The link above for iphonetechie will work with no problem.

Here is link for 3.1 OS (Custom Restore IPSW – Partition: 768mb) on a 3G iPhone
http://www.iphonetechie.com/2009/09/enable-mms-for-iphone-3g-and-3gs-on-3-1-update-through-itunes-jaibreakers-go-ahead/#more-184

Here is a link for How to enable MMS on iPhone 3G and iPhone 3Gs on firmware 3.0 / 3.0.1
http://www.iphonetechie.com/2009/09/how-to-enable-mms-on-iphone-3g-and-iphone-3gs-on-firmware-3-0-and-3-0-1-att/