I figured I need a 3G/mobile data connection for my MacBok Pro, so I got the card that AT&T offers. As an aside, the terms said "free after rebate", but free in America doesn't mean free -- it means that you send in the rebate and then after a while you get some AT&T promotional card or something that you can use on future AT&T stuff. So it's kind of like prepayment for future purchases while meanwhile giving them an interest-free loan. The wonders of business...
So anyway, back to the card. Getting it to work under Mac OS X needs some work, but not too much, once you know where to look. First, as the instructions say, you need to go to this site and download and install the software which is standard Mac OS X application. What you don't find anywhere, though, is what you do after that. You start the software, but nothing happens and you can't connect.
Googling helps. Turns out you have to put some settings into the software's preferences. I found many forum threads such as this one. Turns out you have to configure the thing in Preferences like this.
Password may or may not be necessary. After you do this, it connects and works fine. And 3G is mighty fast, yay! I'm already looking forward to next Friday and the new 3G iPhone ;)
Getting it to work with Parallels shared networking
So far, so good. Now, let's crank it up a bit and say you want to get the thing to work with Parallels. By default, after you do the above, Parallels complains that it cannot connect to network adapter "unknown" when your 3G card is active. What's going on?
Turns out that the GlobeTrotter Connect software creates a new network location profile and automatically switches to it when you launch the 3G connection. This would be fine, except that it is missing the Parallels virtual network interfaces that Parallels has added to your default/automatic profile.
So, what you need to do is to go to System Preferences, Network, and switch to GlobeTrotter Connect profile. Then, add the two missing interfaces. In my case, I had to add "Ethernet Adaptor (en2)" and "Ethernet Adaptor (en3)". I named one of them "Parallels NAT" and the other "Parallels Host-Guest", exactly as in the "Automatic" location. You don't need to touch any other settings.
Just after adding these two interfaces, shared networking works perfectly again now and I can reuse my 3G connection from inside Windows running in Parallels, switching between Airport and 3G connections in OS X however I want.Share