As a college student, you really aren't doing your kids any favors by paying for their college. Its not going to teach them the value of money when they have never earned anything themselves and their tuition is magically paid.

Taking loans and working in the summer/internships to pay it off, without being reliant upon your parents is the ideal to aim for.

After all, I think Warren Buffet said that he plans to give enough to his children so that they could anything, but not enough so that they can do nothing.