以下是引用kmg在2005-3-6 22:24:00的发言：

是不是啊？我想知道！那位大虾知道啊？

I did this in 2001 or 2002, it is pretty easy, just need to be there early in the morning, bring your OPT application receipt and got it instantly.

Basically >90 days.

I don't know how about now. You may want to try. I guess it should still be OK.