Even after you graduate from college, keep your student ID on hand for as long as possible. There are all kinds of perks to doing this; here are a few of them:
1) Student ID's can get you discounts at tons of department stores, even if you're no longer in school.
2) If you still live in your college town, you can usually use the public transportation for free until the ID expires.
3) Your ID can reduce cover charges at bars and clubs, or get you in for free during student nights. Many bard and clubs also require two forms of photo ID to gain admittance, and a student ID is ideal for these situations.
