One point five billion dollars. Or, to put it another way: $1.5 billion. (And yet a third way: $1,500,000,000.)

No matter how you say it, it's a lot of dough. And it's how much Metro says it needs to fund the capital improvement plan called Metro Matters.

A while back in this space, I floated a few modest proposals on how Metro could raise the money (instituting first-class cars, selling naming rights to stations, producing an underground reality TV program).

Recognizing that more brains are better than one, I invited readers to send in their own suggestions. They performed admirably. Why, any one of these might just put us on the express train to fiscal responsibility.

Washington's Phil Frankenfeld proposed something called Thursday Karaoke Night. Once a week, Metro would auction off the right to announce the station stops over each train's public address system.

I like that idea. For some reason, it reminds me of how you see celebrities ringing the bell on the floor of the New York Stock Exchange. I'd certainly pay 100 bucks to ham it up over the microphone: "Good morning, Franconia- Sprrrringfield! Let's get ready to . . . stand clear the dooooooooooors!"

In a more musical vein, Phil suggests Saturday night concerts in Metro Center by the NSO and other groups. Said Phil: "Take the A Train to the kingdom of music!"

Amanda Ligatti, who recently moved to Allston, Mass., from Washington, liked my idea of opening dining cars on the subway but thinks it didn't go far enough.

"Metro should have a happy hour car on the trains during afternoon rush hour," she wrote. "For an additional $2 on your fare, you can gain admittance to this car and pay inflated prices for sidecars, gimlets and Gibsons." (A Gibson, by the way, is gin, vermouth and a pearl onion. Metro's bartenders could replace the pearl onion with a nine-volt battery and call the concoction a "Third Rail.")

Sarah Polaski from the District was surprised that none of the people who have been pushing for slot machines in Maryland or the District have thought of putting gaming parlors in the Metro.

"It's already been done in Russia," she said. "There are several stations in Moscow that have slot machines."

In fact, the whole gambling aspect of Metro has been ignored. Riding Metro has itself become a bit of a crap shoot -- will the parking lot have room for my car? Will the train get me to work on time? -- so why not run with it? Christopher Hellman of Falls Church had a sensational idea about having riders on the platform bet on the color of the next approaching train. This "on-track" betting would be a little like keno.

You could even make it more complicated. Will a four-car train or a six-car train pull in next? Will it be going to Silver Spring or Wheaton?

Eventually, Metro could institute a lottery: Pay a buck to guess the day's total ridership. If you hit it dead on, you win a prize.

Claire Kunkle of Alexandria had a two-word suggestion: pay toilets. "I bet a lot of people would be willing to pay a quarter in an emergency," she said.

I hesitate to mention an idea from Arlington's Elizabeth Holbrook: "Metro could make quite a lot of money by charging The Washington Post a fee for every copy of Express that is left on the train." (Remember: Newspapers don't leave trash; people leave trash.)

Daniel J. Donoghue of the District has what may be the most complicated idea. He proposes that Metro operate only one escalator at each station exit. The rest would be stationary. The lone operating escalator would go up and customers would access it with their SmarTrip cards -- once when they got on and once when they got off.

Riders would be charged by the amount of time they spent on the escalator. Stand to the right and you'll be charged more than if you walk up the stairs on the left.

"This would have the added bonus of encouraging people to run up the stairs on the left and walk up the stairs on the right," Daniel explained. "No more escalator gridlock!"

The revenue stream would be graduated. For example, if you can make your way to the top of the Dupont Circle escalator in less than 30 seconds, you get charged only 5 cents.

"For every additional five seconds . . . you get charged an extra nickel," said Daniel. If for some reason the escalator wasn't working, you'd get a refund, based on how many steps you had to climb.

And how would Metro spend all the money? On escalator repairs, of course!

As silly as most of the ideas were, a few readers sent in suggestions that -- dare we say it -- might actually work.

John O'Hanlon of Germantown thought Metro should institute something like those signs on the interstate that announce which fast-food joints and gas stations are at each exit. Companies would pay to have their names listed on signs inside Metro stations.

It would actually be helpful to know -- as you emerged, blinking, from the underworld -- where the nearest Starbucks or Hecht's was.

And Silver Spring's Harold Congdon, a no-nonsense sort, said everyone has missed the obvious solution: "All employees must take a pay cut just like the airlines have done for 20-plus years. . . . And management should take the biggest cuts."

It's that time of the week again. Join me today at 1 p.m. for my regularly scheduled online chat. It's at www.washingtonpost.com/liveonline. Be there or be quadrilateral.