I am 16 and want to go to an R rated movie?

My mom doesn't care.. she just can't take me. I am 6'4 and I look old enough. My friend looks old enough too (facial hair and all that jazz) I mean, we are 16 and close to being 17 so we won't change that much in a few months. I just wonder if they will card us and if they do, will the excuse that I don't have a photo ID that has my DOB on it work? There are plenty of 17 year olds who don't drive. All I have on me with a photo is my school ID which shows that I am a student at the local high school. My friend is from a different state and doesn't even have his wallet with him... what do you think will happen? We want to see the Hangover 2 and since he's in town for a week, we figured that this would be the perfect time