MacBook Pro 15" and a Option GT Max 3.6
First, after installing OS X 10.6 I couldn't get the thing to work. Then, I deleted both GlobeTrotter references in the Network Control Panel and reinserted the card. As a mjp123 noted in a prior post, reinserting the card causes 10.6 to recognize it again. Using the settings in mjp123's post worked fine for me, but the connection download speed was always <300kbs (and the signal strength bars on the menu never turned black like they used to... they always stayed grey... and it continued to say WWAN not configured). So, I deleted the GlobeTrotter from the Network Panel again. I downloaded the "unsupported" version of GlobeTrotter connect software 1.3.0.164 and installed that. I fired up the software and inserted the card. (Took more guts than brains after seeing posts about Kernal Panics.) It recognized the card and the ATT network. The software created a "new location" called GlobeTrotter Connect in the Network Preferences. I set Account Name to ISP@CINGULAR.COM and Password to CINGULAR1. Hit the Advanced button, selected the "Modem" button, then selected Vendor "Option N.V." The other boxes filled in automatically. Now it connects at 500 to 700Kbps. Not sure why, but now this thing connects even without starting the GlobeTrotter software, just using Network Preferences as set.