> but my plan won't let the laptop connect to the Internet--that's another $15/month T-Mobile is just doing dumb user-agent sniffing at their proxies. Install

> but my plan won't let the laptop connect to the Internet--that's another $15/month T-Mobile is just doing dumb user-agent sniffing at their proxies. Install a user-agent switcher extension/plugin in your browser and identify yourself as a mobile browser and the "please pay for hotspot" message goes away. They weren't disabling anything on your phone. This isn't related to OP's issue. The Nexus 4 has a button to enable wifi hotspot, his Nexus 7 doesn't. That's an Android thing, not a carrier thing. There are hundreds of forum posts about it -- Google did this -- Google shipped a tablet with Android's wifi tethering feature disabled.