Hi all, I was curious if the internet speed was going to be affected depending on whether I tethered via USB or using iOS 4.3's wifi. I did some test and below are my results. Hope it is useful. Just a FYI the circumstances were exactly the same, and i am using a week old 15 inch Macbook Pro i5. I live in Taiwan and my iphone 4 is connected to Chunghua 3G. I used speediest.net to conduct the speed test. Speed test results: wifi tethered: Ping: 57ms download: 3.02 Mbps upload: .3 Mbps USB Tethered: Ping: 61 ms download: 5.26 Mbps upload: .31 Feel free to post your own speed test results.