savingdealz,
ingdirect.com has a way to start a Roth IRA - this is what I used to start my boys out with while they were yet teens and
IF I remember correctly there were no minimums that had to be automated (this may have changed since they had their's there). Once they had a good little amount in there we transfered to Fidelity.
ING DIRECT Orange Retirement Accounts - IRAs - Investing Basics