In a sluggish economy, incubators give fledgling firms a boost. (business incubators)

On a recent July afternoon, activity at Milwaukee Enterprise Center-South is brisk. Some pedestrians pass by, others enter the hulking 120,000-square-foot structure on Milwaukee's south side. Inside, people are working. Really working.

The activity started to pick up in April, when Site Personnel Services Inc. became the first firm to move into the business incubator, and became evidence of what MEC-South officials have known for about five years.

"There are businesses just waiting for an opportunity like this," said Miguel Berry, director of MEC-South, 816 W. National Ave.

MEC-South recently landed another business waiting for an opportunity: Twin Technology Inc., an agricultural machine manufacturer. Several more tenants should move in soon, Berry said.

What's happening at MEC-South has been happening at other nonprofit business incubators for years. Incubators continue to flourish in an economy that over the last year or so has been anything but booming. That makes their role in local business development all the more important.

"In this kind of economy you have many more people with a number of years experience who suddenly find themselves out of work," said Brian O'Malley, director of Milwaukee Enterprise Center-North, an incubator at 2821 N. Fourth St., …