When filmmaker Jeny Crouch set out to make a difference in the lives of her fellow Austinites this summer, she started with the most precious commodity for everyone: time.

As the founder of the grassroots volunteer effort, Moving Difference, Crouch has watched in amazement as a simple, selfless idea to get active exploded into a full-blown viral movement.

All Crouch asked Moving Difference participants to do was to pick an hour out of each week to commit fully to volunteerism. It could be as simple as cleaning up trash in your neighborhood or as scheduled as signing up at a food bank, as long as the action can improve Austin life somehow.

In Crouch's early estimates of Moving Difference's first year, she assumed she could hopefully motivate 100 people to put in one hour each week of the summer, which would put the group well over their intended goal of 1,000 volunteer hours.

As of this past week, Crouch reports that volunteers from in and around Austin have so far logged in over 3,500 hours of volunteer work: three and a half times the goal Crouch had set for Moving Difference in its initial year. Crouch further reports that over 25,000 hours have been logged from cities all over the world.

Not too shabby for an idea that Crouch originally formulated on a napkin from a taco shack in town.

"I never expected the summer of 2012 to be like this," the busy community activator says with pride. "Gobsmacked, awesome and amazing don't do justice to what I have seen this Moving Difference project do. This is about busy people still making a difference one hour at a time."

And while the summer might be unofficially over, there is still always work to be done. (And, of course, volunteerism can happen year round.)

This coming Saturday, Sept. 8, Crouch invites everyone to join in what she has dubbed the Silly Hat Big Clean. Between 8 a.m. and noon, Moving Difference volunteers will don their most eclectic headwear and join in the revitalization of public parks all over town.

If you don't have a park in mind that you would like to work on, Crouch has some suggestions for parks in need. She also adds that the largest contingent of volunteers will meet together at the Mo-Pac underpass of Town Lake at 8 a.m. in order to enact a concentrated, fashion-accessorized cleanup of the surrounding area.

This is the last major planned event before Moving Difference celebrates the end to its first successful summer at sunset on Friday, Sept. 21 with a friendly, informal gathering at the Stevie Ray Vaughn statue at Town Lake.

On that evening, all of the summer's volunteers are reminded to stop what they're doing wherever they are, take time to watch the sun go down and think about the interconnectedness of the planet and the effect that we can each have by taking even the smallest actions.

"It is people... quiet and steadily doing good that makes this world a better place," Crouch writes on the Moving Difference website. "I never imagined 25,000 hours. Not from a little taco napkin idea certainly."