Apple had announced availability of OS 3.0 on june 8th for developers and june 17th for rest of the users. But as expected, 3.0 has been leaked by some developer. You can get 7a341 Final release of OS 3.0 here:
iTouch OS 3.0
iPhone 2G OS 3.0
iPhone 3G OS 3.0
I’m not responsible for any issues you might under by downlaoding from torrents. At your own risk!
After installing OS 3.0, I did some initial review, Found it to be a worth upgrade.