Take advantage of the ROTH IRA while that option still exists. The money you contribute to a ROTH IRA is not tax exempt but when you reach retirement age and begin your withdrawals, you will not have to pay taxes on the amount of your original contributions OR the interest and capital gains you realized in that account over the years. There is a limit on the maximum amount you can contribute to an IRA and that amount could change based on the composition of Congress over the next few years but ROTH is the way to go because you have more control and better long-term tax advantages.
I suggest you open an account with Sharebuilder or some other online investment firm that offers ROTH IRAs. If you have more to invest than the maximum permissable amount, park that money in an interest bearing money market account with the same investment firm and let your cash build up until you have graduated and established yourself in a secure job. That way you have a good start on your retirement and also a cash reserve available for either retirement or emergencies as you deem appropriate.
Remember, money doesn't have to be sitting in an IRA account of some type to be earmarked for retirement. People used to save up for their retirements with simple savings accounts. And it worked. The benefit of the online investment IRAs is that you can select from a variety of investments to diversify your holdings. You manage the investments instead of somebody else managing your investments.

