FINANCIALLY strapped state and local governments are missing something important in their tax and budget deliberations.

You know the problem by now. The economy is slowing, tax revenue is decreasing and federal aid keeps declining -- yet citizens somehow expect government officials to balance budgets without slashing services. Raising income or property taxes is political suicide, and most other aspects of our lives -- from food to gas -- already are taxed till it hurts. So what to do?

The only practical solution is to find a significant new source of revenue. Happily, one exists. A huge portion of the population, good citizens otherwise, have been largely eluding the government revenue enhancers. But no longer. They are sitting ducks, an ideal target: They have a bottomless supply of disposable income -- and virtually no political clout. Our long economic nightmare at last has the perfect remedy: a package of junior-grade "sin taxes." Or to put it more bluntly, it's time to tax our kids.

Spend time any afternoon at Tysons Corner or White Flint or the other teen-heaven malls. Who's flashing the big cash? Not Mom and Dad; they're counting pennies to pay the groceries. It's all the young Donnies and Maries, debating the merits of this sneaker or that beach trip.

We can start by imposing a surcharge on allowances. This will be tricky, because traditionally much of it is unreported income. But tax officials already have many diabolical ways to squeeze full reporting and compliance out of adults, so parents can be expected to cooperate in disclosing their transactions with younger members of the household.

That done, which sins are likely to be most revenue-productive?Surely we should impose a huge levy on phone calls that last more than 30 minutes. We all know who'll pay the most for this, so the tax must be carefully constructed to avoid charges of gender discrimination.

Designer jeans should be a gold mine. I say, the tighter the fit, the tighter the tax squeeze on the young buyer.

Some taxes might be more easily accepted if they were earmarked for appropriate purposes. A hefty pizza tax, for example, could provide all the money we need for college buildings. Tom Cruise movies might be taxed a dollar and the proceeds used for driver education.

And we can't avoid taxing toys. If a 5-year-old has enough dough for G.I. Joe, he can also help support the police department.

We also should give governments broad powers to impose stiff temporary taxes on certain "fad" toys. Why not jump on the Teenage Mutant Ninja Turtles gravy train before these hot-selling characters become shells of their former selves?

Nintendo games offer an additional bonanza. There's nothing in the Constitution to prevent Big Brother from charging fees each time they are used. In fact, how about double taxation for games played before the homework is done?

A new federal tax on admission to Disney World would no doubt be challenged as discriminatory, but what stands in the way of a special airport levy on round-trip fares to Orlando around the time of spring break?

Steep taxes on Adidas, Benneton, Pierre Cardin, Gucci and other cult imports should be politically palatable.

How long can this fountain of youth-dollars continue? After all, today's teenagers will become voters some day. But at about the same time, they will also become parents -- and the tax shoe, the revenue Reebok, will be on the other foot.

If all else fails, the federal government could take the ultimate step: Nationalize all surf shops and claim the proceeds from those uncounted millions of gaudy T-shirts polluting our fine country.