Except iOS has tethering, it's just disabled on AT&T. Says more about the US mobile market than it does about iOS.

it's not even disabled on AT&T, you just have to pay extra for it.

Actually, even that isn't entirely accurate anymore. Apparently tethering is included in the new 4GB data plan (which is $45, to the 2GB plan's $25).

exactly. I've got an ancient (2nd gen) iPhone on which I spend about $30 prepaid and it's been tethering fine for years. I know, because I use the tethering regularly

Curious, I often bring an iPhone to the USA and put a prepaid SIM in it when I get there, last few times I got an AT&T SIM, the tethering option vanished from my preferences. With a TMobile SIM, I can tether, but only at EDGE data rates, not 3G. (Last trip, I use AT&T in the iPad and tMobile in the phone, seemed to be my most cost effective set of options)

TMobile uses different frequencies, which is why you'll only get EDGE data rates with that TMobile SIM.

Can't help, sorry. My experience is with Telstra in Australia

Let's see. Android phones with unrestricted Tethering and Wi-Fi hotspot are Nexus One, Nexus S and presumably Galaxy Nexus.

Tethering on any Droid phones are encumbered by Verizon. You have to pay the tethering plan to have this feature enabled. The same goes AT&T Android phones with "crippled" tethering capabilities.

iPhone supported carrier-sanctioned tethering pre-iOS 4 (iOS 3.x in 2010), just not in the US with AT&T. Different carriers handle it differently.

Android phones on T-Mobile have tethering enabled. At least my still-locked HTC G2 does. As far as I know, I'm not paying extra for it.

That's because T-Mobile allows it. I mentioned specifically Verizon and AT&T for locking the features. I'm not sure how Sprint deals with the whole tethering.

As far as we know T-Mobile is a lot more "customer friendly" since they're running 4th out of the big 4 Wireless provider in the US.

Doesn't side-loading tethering apps work on Verizon (and newer AT&T phones)?

Of course, they can still get you via traffic analysis and other tricks, but that is a different sort of issue.

Azilink is awesome on Android:

https://code.google.com/p/azilink/

Have never had an issue with it.

I think Google gets away in part because the telcos are afraid of Apple. Similarly with how Amazon got DRM-free content at a lower price because the labels wanted to create some competition to iTunes.