iPhone 3.0 Gold Master is here, you can download it at the following links, no registration is required..
iPhone OS 3.0 GM Seed for 3G iPhone http://rapidshare.com/files/242393004/iPhone1_2_3.0_7A341_Restore.part1.rar http://rapidshare.com/files/242393541/iPhone1_2_3.0_7A341_Restore.part2.rar http://rapidshare.com/files/242393756/iPhone1_2_3.0_7A341_Restore.part3.rar
iPhone OS 3.0 GM Seed for 1G iPhone http://rapidshare.com/files/242408108/iPhone1_1_3.0_7A341_Restore.part1.rar http://rapidshare.com/files/242408829/iPhone1_1_3.0_7A341_Restore.part2.rar http://rapidshare.com/files/242409591/iPhone1_1_3.0_7A341_Restore.part3.rar
Enjoy.
[...] When redsn0w asks for your IPSW browse and select the 3.0 firmware file (presuming you still have it on file, if not you can download it here) [...]