You'll find by looking through most requirements for graduate school that a 3.0 or higher must be attained. Some schools have a 2.75 GPA requirement, and a select few even have 2.5 GPA requirement. I'm not sure how rigidly they base selection on this but if you're above a 3.0, you'll definately have a chance at getting into a school. It may be harder to get into the top-tier schools because of this, but if you can follow through with a wonderful score on the PGRE (such as 95%), and have had at least some research experience, you shouldn't have a problem finding a program that will accept you.
Make sure that you are well prepared for the test and have looked through the practice tests online, this will be a big help if you can score well on it.
As far as a friend getting a score on the Physics GRE, I do not have any friends who have taken the Physics GRE, nor can I recall someone in the last three graduating classes from the Physics Department at my school taking the test. I guess the people around me aren't as ambitious to go to graduate school.
Hope this helps.