FWIW, Foxfi is working on my AT&T GN3. As others have said, just hit the home button when the popup appears. Also, I've noticed when connecting with my laptop, full internet isn't available for the first 30 seconds or so, so just give it time...
Thanks guys (I'm in the same boat as inmotion). To get tethering to work, I used Titanium Backup to freeze Tethering Provision, and I then installed FoxFi.
Got it from here: https://play.google.com/store/apps/details?id=com.foxfi2
When I activate Tethering I get a "settings has stopped error" - but the FoxFi & everything else stays working.
You rock!! I dont' use foxfi but I use ES File Explorer, which has tethering and giving me the AT&T pop up. SO I tried your trick (just hit home) and I'm tethering! no text message yet, will report back if it comes.
You have to enable USB Debugging mode in order for it to work. I had a heck of a time finding it, so here is a quick howto...
From home, press "Apps" menu, press "Settings", press "General" tab, press "About Device", press "Build number" seven consecutive times and you should get messages about having "Developer Mode" being turned on. That's it!
Hit back and you should now see a new "Developer options" selection in the menu. Press "Developer options" and just check mark "USB debugging" if you want to enable it.