Not sure how in depth you need to be; but how about drugs in cycling. There are some great discussions about the ethics of drug use in sport in the phylosiphy of sport journals with some very good cases for allowing drugs in sport!!!!! Combine these with the personal accounts from cyclists autobiographies and newspaper cuttings; let the argument comense.
Or how about a 'should london (or anywhere else) hold the olympics? Some interesting points financialy (not many olympics have made a profit), local v's national interests (i.e. london v's britain), the politics (i.e. hitlers olympics), terorism (i.e. the bomb at atlanta or the munich disaster), sexism, racism, coruption in the olympics, will athens be built in time, drugs, fixing in sports like gymnastics, amature or professional competition, etc. etc. Sure you'll have more than a few pages to work on there and there are some great books on almost all of the topics above.