Update on July 22 ( July 21 in the U.S ):

Here's my personal experience and tips, hope this could make sense for your travel in Beijing:

1. The subway security check
   My experience: The line 10 subway in Beijing is now also asking people to take security checks.
   Tip: Please don't bring strange "liquid" with you, or you will be asked to take a taste ( what if that's your urine for a health check? )
2. The university security check
   My experience: The UIBE (University of International Business and Economics) is asking people who enters its campus for related "credentials".
   Tip: Please find a student who studies in the specified university you wanna enter. Or you may have to fill a very complicated form :)

Though we all know that "security checks" are only a palliative (measure) in the fight against terrorism, we have to face something sometimes, here is the picture:

(I am sorry that the picture is removed for unknown reasons)

Anyway, I don't care about the Games itself much, nor do I care about the politics, I just how that everyone can be safe and undisturbed.