Maybe, it has been known by many user, but this is my first time to successfully use such function in China trip today, and it is great! (I’ve tried it before via iBook G4 and shared to BlackBerry Curve 8320, but failed.)

Assume you are on a business trip with your iBook (or MacBook) and iPhone 3G. It is too expensive to use the data roaming of iPhone 3G & you have turned it off. After a day of meetings, you are back to hotel & plug your laptop to the hotel internet via ethernet (paid or free). Then, how about your iPhone 3G? One option is login to the hotel wifi. But, not all hotel provide wifi. And you may have to pay one more connection fee. So, with your fine Mac OS X, then, your iPhone 3G can also go online and check email, browse internet etc. 

So, let’s starts:

1. Go to “System Preference” & click “Sharing” under “Internet & Networking”, then “Internet”;
   
    
2. In “Sharing your connection from:”, choose “Built-in Ethernet”;
3. In “To computers using”, choose “AirPort”;
    
4. For safety, better set up secure wifi. So, click “AirPort Options…”
5. Then, type your preferred “Network Name”, “Channel” (leave them to default if you like). Choose “Enable encryption (using WEP)”, type your password twice in “Password” & “Confirm Password”;
    
6. Time to click “Start” in “Sharing/Internet” & “Start” in warning notice again.
    
   
7. So, you’ve shared your internet connection via AirPort. See the AirPort status with an arrow. 
    

Then, it is the time to configure your iPhone 3G:

1. Open “Settings” & tab “Wi-Fi”;
   
2. Now, you see the network your have created. Tab it, enter the WEP “password” you have set in your labtop & tab “Join”;
   
3. You’re DONE! See the tick beside your network & the Wi-Fi logo on the top status bar!
    

Important Reminder: remember to “Stop” the Internet Connection Sharing after use!