Talking a long walk up Spring Hill the other day, climbing the city steps through an area where I could have used a machete (for the flora, mind you, not the fauna), I found a stray blue plastic bag at the summit.

Before I reached flat ground again, I had that bag bulging with empty aluminum cans.

Hence my brainstorm.

OK, maybe it was more like a brain drizzle, but it prompted me to send an e-mail Tuesday morning to a score of people and organizations, hoping they might agree I'd come up with a dumb idea whose time has come.

You see, I'd begun my walk only for the exercise. Only after seeing so many dozens of empties along the way did I wish I'd brought along a blue bag for the recyclables.

Seeing how easy it was to do some good on my little workout, I wondered what might happen if thousands fanned out one fine Pittsburgh day for exercise and altruism. What if we made a massive organized effort to pick up every last empty can, bottle and jar we could find -- and made it a party?

I'm aware anonymous patriots are already out there snagging and bagging litter on their own. The very morning I took my walk, I came home to read Boris Weinstein's essay in the PG, wherein the retired marketing executive asked the citizenry to join Citizens Against Litter and help clean up our collective mess.

The Redd Up Pittsburgh Web site at www.redduppittsburgh.com, legacy of the late Mayor Bob O'Connor, has a Monongahela River cleanup scheduled for this Saturday at 9 a.m., starting in Duck Hollow.

All that is great but I still think a one-day, bags-out Trashapalooza is just what this town needs. I'd suggest we concentrate on recyclables because that would grab people's attention and also defray the cost of hauling it all away. That waste is worth a little money.

Early replies to my e-mail have been encouraging, though some argue that the only answer to the litter problem is enforcing litter laws. Others suggest instituting a small deposit on bottles and cans, a reality in 11 states. A spokesman for state Sen. Jim Ferlo, D-Highland Park, said he's working on a bill that would initiate a deposit of 10 cents.

Bob Regan, author of "The Steps of Pittsburgh,'' told me, "I was living in Boston when they enacted a nickel deposit on bottles and cans, and overnight it was clean. I saw it happen.''

We can have the public policy argument later. Right now, on the 42 miles of city steps alone, there must be an empty every foot. That would be more than 220,000 bottles and cans. They're also lying along streets, alleys and sidewalks; they're in parks and vacant lots. You know how sloppy ginger ale drinkers can get.

I have no idea how many empties we'd find, but I'm told that in Hazelwood this past Earth Day, about 100 volunteers filled a 20-yard bin with recyclables, which some estimated as a ton. They filled two more 30-yard bins with pure trash.

Note to self. Contact Guinness to see about world's record.

This should be a party, but it's been years since I threw a kegger, so I e-mailed the Hash House Harriers (a drinking club with a running problem), PUMP and Ground Zero (bringing back Downtown one beer at a time.) My original intention was to contact only groups that mix drinking and public service, and then I realized that in this town that doesn't exactly narrow things down. Picking up empties should seem almost a duty if not a calling.

I'm rambling now, but I think there's at least the germ of a good idea here and, if so, someone on my e-mail list can recommend a good hand soap.

Most of us can remember a time decades ago when people who ran around outside in gym shorts were thought loons. As I walked Saturday with bulging bag, more than one passer-by looked at me as if I had a third eye. But suppose we made aerobic altruism like this as commonplace as jogging?

What say you? If, when we're through, we found we hadn't reached 100,000 empties, we could discuss how to do better next time as we made more.