Alongside today's news that Apple has finally released the iPhone/iPod Touch OS 3.0 to the public (download it by opening iTunes, connecting your iPhone or iPod Touch and clicking the 'Check for Update' button), some websites are noting that it is easy to enable tethering on your iPhone, even if AT&T hasn't officially announced support for this feature.

Tethering is great for small Internet browsing sessions, or when your iPhone just isn't enough to do what you need to do (for instance, adding content to a website, or uploading a large file). But don't Tether too much: First, if a lot of people are tethering, it can slow down the network for everyone else, and second, your iPhone's battery takes a huge hit (even if charging) while you're using it's 3G signal for tethering.

[NOTE: Visual Voicemail may stop working after you follow the steps below. To get it back, simply go to the Settings app, tap on General, then Network, then Cellular Data Network; tap on the "Visual Voicemail" APN and change it from wap.cingular to acds.voicemail.]

Following the steps outlined on Mac Megasite:

1. Make sure you've upgraded your iPhone to the 3.0 software.
2. Download this Disk Image from Gizmodo (there's a carrier settings file inside that you'll need).
3. Quit iTunes.
4. Open Terminal (in Applications > Terminal).
5. Type in the following command (without the "a.") and press Return:
   
   1. defaults write com.apple.iTunes carrier-testing -bool TRUE
6. Quit Terminal.
7. Plug in your iPhone and open iTunes (if iTunes doesn't open automatically).
8. Click on your iPhone in the "Devices" section in iTunes.
9. Holding down the Option key, click "Restore."
10. A window will pop up asking for the location of the restore file - navigate to the .ipcc file that's inside the disk image you downloaded earlier, and choose it.
11. Wait for your iPhone's carrier settings to be updated (it will only take a few seconds).
12. Now, your iPhone will show some sort of Terms and Agreements screen. Press OK until it goes away, then go to your iPhone's home screen.

To start Tethering from your iPhone to your Mac, just go to the iPhone's settings app, tap General, then tap Network, and finally Internet Tethering. For more on Tethering, visit Apple's website.