I have a lease for two years. help?

I signed a lease for two years back in nov of 2010. its a nice place. I pay $870.00 for rent. since then this place has gone down hill. the young guy across the way ( in front of us) keeps coming over asking to borrow cig, then he called my sister a f*** B**** all because she would not give him one. then there is a young guy on to the left of us who is also in his early 20's, he has traffic going in and out of his apt of young teenagers all kinds of day and night. he's very loud.I think that he is drug dealing, but not for sure. but all the sign are there. the kids would come over and before you know it there all outside in the front drinking. I have to close my shades just so I don't have to watch it. and that is not far to me nor my roommate. she has already told me that she is thinking about moving out because she cant handle it. We pay the most here. I had told the landlord about things But it just seems that he don't do anything about it. I wish that I could break my lease and get out of here. what kind I do about this? Is there anything I can do?