So this is it, the big day, it's finally here: G-20 Day!

For days in my North Side neighborhood, we've watched helicopters fly overhead and phalanxes of police motorcycles zoom down streets in a show of force for people who hadn't yet shown.

Now everybody is here, and Pittsburgh is more than ready.

Local authorities, working in conjunction with the U.S. Department of Overreaction, closed the walkway on the Fort Duquesne Bridge early in the week, just to be on the safe side. That only prompted the acrobatic protesters of Greenpeace to set up shop downriver yesterday morning. They lowered themselves from the West End Bridge to unveil this sign:

"Danger; Climate Destruction Ahead; Reduce CO2 Emissions Now."

This prompted all kinds of media and police to race to the bridge in vehicles fired by internal combustion engines so, hey, good job, guys!

The sign couldn't even be read from the Downtown side of the bridge, where about 130,000 people usually work -- just not yesterday. I biked in from the North Side with my wife about 9:15 a.m. and we had the Roberto Clemente Bridge pretty much to ourselves. The bronze Clemente was one of the few other people we saw.

"It's a very nice city," visiting dignitaries must be saying in calls home. "Nobody lives or works in the heart of Pittsburgh, so I guess that's how they keep it so nice."

So far, the most comforting knowledge to be gleaned from G-20 preparations is that America will never become a permanent police state. We couldn't afford it.

City police spent much of the past week hassling a couple of groups who came here in old school buses to serve food to protesters. A federal judge has given police plenty of rein to be aggressive, but no city or nation could possibly expend this much money indefinitely just to keep granola and tofu from the masses.

This is yet another reason to never volunteer to cook.

Many in Pittsburgh now see any scruffy visitor as dangerous, which can at times make us look like a bunch of fraidy cats. Only four students showed up on a Mount Washington overlook yesterday morning for a peaceful demonstration as part of a Youth Economic Summit, when 100 had been expected.

Evidently, two schools canceled in the wake of an e-mail that's been going around from a well-meaning guy who fears this will be a week of protesters throwing bricks through windows and setting off stink bombs.

Consequently, the media outnumbered the demonstrators on the Mount Washington overlook and cops of various badges outnumbered the media for an event that was about as volatile as lint.

I embrace the philosophy espoused by Chazz Palminteri in "A Bronx Tale." Welcome people as guests until they behave badly, and then get as tough as you have to be.

I've read some of the lefty commentary on the Internet from people spoiling for a fight in Pittsburgh. The G-20 Wrecking Crew, for instance, urges destruction in "the expanding bourgeois cancer of Shadyside, the dividing line of gentrification represented by Penn Avenue."

Puh-leeze. Street-corner philosophers arriving from Europe and America's coasts have no idea of the real problems in Pittsburgh. Gentrification? This ain't San Francisco, New York or London, where population pressure drove affordable homes out of reach. Here in Western Pennsylvania, we've been losing population and knocking down abandoned homes by the thousands, so anyone coming in to fix up an old home and spend money and pay taxes in our walkable city or our old mill towns is part of the solution, not the problem.

"I think these people need to get a big (insert bad word here) clue before they come into someone else's town and tell us what we need to do," Pat Clark of Friendship said when I told him about this "Penn Avenue dividing line," and Clark is nobody's idea of a conservative.

I've been drifting around in this column like a Greenpeace activist hanging from a bridge but, the truth is, the protests have seemed unfocused, too. Each group has a particular agenda but there seems no unifying notion beyond "G-20, bad."

It could get more interesting today, but most Pittsburghers will stay well clear of town. With various businesses temporarily closing, I've heard the G-20 compared to a two-day snowstorm.

That's a fair analogy except, in this one, some of the flakes may be wearing black T-shirts.