Minneapolis could take a few pointers from the scene last Thursday in downtown St. Paul.

It was -- and is -- the day for street food-lovers to hit the city's streets. I don't know that I'd invoke the words critical mass, but four of something is definitely something. Last Thursday, three food purveyors -- the Chef Shack, the Magic Bus Cafe (above) and She Royal -- were lining the Wacouta Street side of Mears Park. A fourth, the meals-on-wheels version of 128 Cafe, was feeding downtowners on Wabasha St. at 5th St., in front of Ecolab Plaza.

Business seemed steady, and diners looked more than happy. I was ecstatic. For one thing, it was great to see the Magic Bus Cafe, a retrofitted 1978 Chevrolet school bus, out of its normal farmers markets environment (it's a staple at the Midtown Farmers Market and the Uptown Market) and turning heads on a busy city street.

"We're going to try and make downtown St. Paul a regular Thursday thing," said co-owner Chris Lockyear. As for Minneapolis, "I sure wish we could," he said. "There are so many good places we could go."

Amen. Seriously, what's the deal with Minneapolis? Why does the city make it so difficult for vendors to do business? "We've been through a hard time with the city of Minneapolis," said She Royal co-owner Samson Benti, who was parked just down the block from the Magic Bus Cafe.

Mobile food vendor licenses for Minneapolis and St. Paul. Guess which one cost more?

Benti had finally received his Minneapolis license that day, a major cause for celebration. It cost close to $600 and is good through April 2011. Compare that to his St. Paul experience, where he acquired his license a month ago, and his roughly $200 investment bought an entire year. Unlike Minneapolis, which requires vendors to procure a specific approved sidewalk spot (a strategy which does have its advantages, namely that it provides important continuity), St. Paul only requires that the truck's operators feed the parking meter (or meters). Drive up, drop in a few quarters and get cooking. Why can that work in St. Paul, but not its sibling to the west?

The spiffy She Royal food truck, making a rare St. Paul appearance on Mears Park. Look for it in downtown Minneapolis this week, near the Orpheum Theater and the Greyhound Bus depot.

The good news is that there is some traction down at Minneapolis City Hall. Benti said that, starting July 5th, he'll be a daily fixture at his newly approved Minneapolis berth at 1st Av. N. and 8th St. In addition, Sonny's Ice Cream is now serving six flavors of its meticulously crafted ice cream -- do not, under any circumstances, miss the salted caramel -- from a portable scoop shop in front of the IDS Tower at 8th St. and Nicollet Mall. Look for it Monday through Friday.

Meanwhile, the Chef Shack has set up camp in a parking lot at 5th and Hennepin (and wisely avoiding some of the city's red tape by skipping the whole sidewalk setup), serving Monday, Wednesday and Friday mornings and afternoons, and the Brothers Deli's pastrami cart is scheduled to debut this week in front of Macy's on Nicollet Mall at 8th St. But why is the city dragging its heels on licensing? Summer is flying by, and the season won't last long. Still, disbelievers and naysayers who predict that a thriving food cart scene will lure dollars away from established, rent- and property tax-paying brick-and-mortar restaurants only have to look to cities with viable street food options to see that the more the merrier is the true economic force at work. Critical mass begets critical mass. You want a lively downtown? Then get people on the streets.

A first-rate portable lunch: Red beet sauerkraut over a fried, split hot dog at the Magic Bus Cafe. It's even better with brown mustard.

Back to the Magic Bus Cafe, which knows how to dress up hot dogs (split, and fried hot dogs, that is). For breakfast, there's one topped with scrambled eggs and bacon. For a color splash, check out the sauerkraut made with beets and tons of garlic, or for some unabashed heat, order the "Mexicali," which is loaded with hot peppers and a super-spicy relish. The daily special was a doozy: blue cheese, crispy celery, a dash of sour cream and a hot Buffalo wing sauce. All of them fall in the $4 to $6 range, and all can be made with tofu dogs for those not into all-beef hot dogs.

"I like the idea of bacon on a hot dog," said my friend as he took a hefty bite out of the well-topped breakfast dog. Meanwhile, I was wolfing down the menu's one non-dog item, a thickly sauced barbecued pulled pork, piled high on a whole-wheat bun. I hated to give up the last bite, but I handed it to my friend. "We've really got to get to Lowertown more often," he said.

The bummer where She Royal was concerned was a timing issue; we arrived too late to get a crack at the truck's vegetable sampler. Instead, I feasted on a pair of terrific sambusas, small triangles of delicate fried dough filled with ground beef and chopped vegetables and served with a scorchingly hot pepper sauce. Not bad for three bucks, not bad at all.

For dessert, we were craving doughnuts from the Chef Shack, but they weren't on the menu that day. Drat. Instead, they generously sent us about six blocks to the west, where we found a parking spot ("Is it always this easy to find on-street parking in downtown St. Paul?" asked my friend. Um, yeah.) and got in line at the 128 Cafe truck, where we quickly developed the kind of obsessive crush that can quickly tumble into a restraining order.

Be on the lookout for the 128 Cafe's new portable cafe, where the restaurant's stellar ribs are available in quick-service format.

The restaurant, located across the street from the University of St. Thomas in St. Paul, has always been known for its spectacular baby back ribs, and its new truck is no different. As street food goes, the prices skew towards the high end -- $11 for those ribs -- but the results definitely deliver. Particularly the main event. Each abundant short rack is all about crispy, roughly charred skin that's liberally brushed with a sweet-hot sauce and grilled until it's nicely caramelized. Underneath is plenty of all-off-the-bone meat that's outrageously, mouth-meltingly juicy. It's served with a crunchy and cool cabbage-pepper slaw and nicely salty potato chips. Perfect.

Top-of-the-line street food lunch: Ribs with chips and slaw from the 128 Cafe's food truck.

As if that wasn't enough, they were serving a stunner of a summer salad ($7): greens, fennel, herbs and tangy chevre tossed in a bright citrus dressing and finished with tender stalks of grilled asparagus and tart, thinly shaved pickled carrots. Either was enough for lunch on its own; together, I felt as if I were treating myself to one of the best lunches downtown St. Paul had to offer. (Also on the menu: pesto-shrimp skewers, ginger-marinated beef skewers and a BLT dressed with a chile-lime aioli, all $8).

This beautiful blend of grilled asparagus, field greens, chevre and pickled carrots came out of a truck.

When I asked if they'll be back next Thursday (because, well, that's where I plan to be), the friendly guy manning the window nodded enthusiastically. "We like Thursdays here because there's a farmers market down the street, and we catch a lot of that traffic," he said. "We go wherever we can find a parking spot." Someday, perhaps that will hold true for Minneapolis. If that ever happens, can the parking spot be somewhere close to my office?

My one regret of my noon-hour Capital City street food field trip? That I forgot to stop by Meritage for crepes, which are made to order from a stand on the sidewalk in front of the restaurant every Tuesday and Thursday. Next week, definitely.