Wondering how to get the iPhone OS 3.0 before your friends? Well…
Beta versions of iPhone OS 3.0 have leaked on the www and is freely available for iPhone users to download and try. The torrent firmware is available for download on the links provided @livecrunch.
Though iTunes won’t officially show you the 3.0 update, when you connect your iPhone but pressing the Shift Key + Update button on the iTunes, will let you select any custom firmware to be uploaded on the device (select the iPhone 3.0 file you downloaded). Mac Users need to hold Option Key and hit Upgrade button with a mouse click.
If you have tried this, do give us your feedback. Engadget had a video live with the 3.0 firmware in use. So we are pretty sure this works.
Note: Installing beta firmware can harm your device, void warranty etc etc. Try at your own risk.
Update: Firmware 3.0 beta is meant for developers as of now. Downgrading to 2.x again would be tricky. Again, try at your own risk (and do let us know how you did ;))
Update: Here is why you SHOULD NOT UPDATE TO 3.0 YET