In March the White House Council on Women and Girls hosted a game-changing forum on workplace flexibility that was attended by a host of heavy hitters, from Secretary of Labor Hilda Solis and Council of Economic Advisors chief Christy Romer to leaders from some of the country’s most forward-thinking companies.

Also in attendance? The nation’s first working mother and father, Michelle and Barack Obama. Both spoke of the tough juggling act they faced as young parents. “For many years before coming to Washington, I was a working mother, doing my best to juggle the demands of my job with the needs of my family,” said Mrs. Obama. “While I did the best that I could at work and at home, I felt like I wasn't keeping up with either one of them enough.”

The impossibility of “keeping up” is a fact of life for working mothers. But smart companies are doing what they can to help. Here are five firms whose inventive flex policies and practices lead the Working Mother 100 Best Companies in helping moms to keep all the balls they juggle in the air.

Chicago-based financial-services firm Grant Thornton offers a variety of flexibility “flavors” that let employees craft a schedule that fits their lives, work from home to save on commuting costs (and time), opt for a nonlinear career path, take a leave (with medical benefits), phase back to work part time or even bump their hours up if a spouse has lost his job.

Global professional-services giant PricewaterhouseCoopers turned the economic downturn into a win-win situation for itself and its staffers, avoiding layoffs and compensating for the lack of raises by offering four work-free Fridays in the summer, extra time off throughout the year and other perks.

At Bank of America, work flexibility extends to where as well as when people work. The banking behemoth’s My Work program supports more than 15,000 employees who take care of business from fully equipped home offices or satellite locations close to where they live.

For the hard-driving employees of KPMG, the professional services firm’s new sabbatical program is a welcome benefit. More than 450 employees signed up in the first weeks after the program’s launch, opting to take between four and 12 weeks off while still earning 20 percent of their salary.

Minnesota-based McGladrey lets its people flex their entire career. The professional-services firm allows staffers to take up to five years off to focus on personal interests or family, while providing them with subsidized training and short-term assignments to keep them up to speed.

See Best In Class in Flexibility in pictures