iPhone 3G 3.0 Final Release *Tested* Developer account not needed!
This has been just release from StealthBravo on Twitter! All credit and efforts go to:
http://stealthbravo.com/blog/
INSTRUCTIONS:
1. Download .rar files & Extract to folder.
2. Open iTunes 8.2 (or Download the Latest iTunes 8.2 and install)
3. Connect iPhone, Backup if necessary (contacts, pictures, etc.)
4. Go to summary tab of iPhone, on PC hold shift and click restore button.
5. Select the extracted firmware you downloaded from this post.
6. Done! Sit Back and let it do its thing....
Note: You do not need to be signed under a Developers account. Anyone can upgrade to this 3.0 Firmware.
Note: You cannot use this firmware with quickpwn or any other jailbreak/unlock software yet. So far its not jailbreakable. Soon Very Soon! Stealth and Dev Teams are working on it as this post goes up. This is the official firmware that only updates to 3.0

iPhone 3G 3.0 Final Release Rapidshare.com Premium Link:
http://rapidshare.com/files/24240666...store.rar.html
iPhone 3G 3.0 Final Release Rapidshare.com Free User Links:
http://rapidshare.com/files/24287442...part1.rar.html
http://rapidshare.com/files/24287576...part2.rar.html
http://rapidshare.com/files/24287713...part3.rar.html
1G, 2G coming soon, and ipods!
W00t! Say thanks comon!