Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
"Though, I don't think you can swipe the card twice at the subway and the turnstile will let 2 people go through."
You can, and the turnstile will remain unlocked for two rotations. But it also works the way you are doing it.