According to Wikipedia there's an "approach to planning and decision-making which reverses the working process of traditional budgeting. In traditional incremental budgeting, departmental managers justify only variances versus past years, based on the assumption that the "baseline" is automatically approved. ... Every line item of the budget must be approved, rather than only changes. During the review process, no reference is made to the previous level of expenditure." (http://en.wikipedia.org/wiki/Zero_Based_Budgeting)
I would like to see Zero-Based Budgeting to be fully implemented. If a Government Department has to justify every expenditure in advance, then the Unused money can be cut out without any harm.
It does have the downside of a higher learning curve, but computers can help!