Loans. Be prepared to start paying loans off 6 months after your graduate for subsidized loans and immediately after you graduate for unsubsidized loans. Pay attention to interest rates and consider consolidating your loans based on the market.
Health Care. Your college probably offered a relatively cheap health care plan or else your parents plan from work covered you while you were a student. Expect your cost of health care to increase significantly upon graduation. One way to alleviate this problem is to get a job with health benefits. Even if your company offers health benefits, however, prepare to pay because recently companies have been requiring a higher deductible and a higher per-employee contribution.
Car Insurance. When you graduate you will no longer qualify for the "good student" discount. Your insurance may also increase since driving to work [instead of walking to class] may cause your yearly mileage to increase.
Public Transportation. By attending college you may have had a discount on local public transportation. You may have also been accustomed to a free shuttle service around campus. In the real world, you will have to pay full price for public transportation and the bus will probably not run as frequently or be as peaceful as the campus shuttles.
The Gym. Your college probably had a gym with a free or discounted membership. After graduation, you will now have to find another way to work out or pay to join another gym. You may be able to alleviate the cost of a gym membership by joining with a friend or finding a discount through your company.
Travel Discounts. From discount train tickets in America to discount Euro-rail tickets in Europe, students often have amazing travel discounts. After graduation, you no longer have an automatic discount because you are a student. After graduation you must find your own discounts.