We are constantly reminded that art is a matter of opinion. One man's trash is another man's treasure. One man's art, another's annoyance. Graffiti is ever-changing, and is evolving from a defacement of property to a welcome art form adorning public space.

The Street Sign Project - a small, worldwide grassroots phenomenon started in Tacoma - takes the idea of public art a step further, to its evolutionary phase. Peppered throughout T-town, you may have noticed bits of non-defacing art that relay messages (of sorts), and perhaps unite the community at the same time.

It slaps me in the face when I least expect it:

"REALLY LOVE SOMETHING," one exclaims during my drive home from work.

"BEYOND YOU," says another on Pacific near the art museum.

They're everywhere, really, if you look - like little secret-squirrel messages waiting to be read and inspiring a movement. "If somebody really doesn't like one of our signs or tape networks they can take them down and return the area to its regular dull state," says the person purportedly behind it all.

"Most of our projects are about encouraging others to join in the fun and contribute to a more interactive and lively public space. Anyone with a piece of cardboard and a paintbrush, or a roll of duct tape, can be a part of Street Sign Project," says the Tacoma-based founder of the Street Sign Project, anonymous for this interview by choice though he's been identified in the past by Tacoma KOMO. The Street Sign Project has been active in Tacoma since at least February, powered by a core of artists previously associated with the Peabody Waldorf Gallery, Spaceworks Tacoma and the Personal Power Company.

According to the official Street Sign Project Facebook page, "In the modern world we are constantly bombarded by sings. Billboards and giant digital displays littering the skyline, the sides of buses and cars, in the supermarket isle (sic), on the television and computer screens. These are placed by companies intent on separating you from your money by convincing the public that buying things also buys happiness. So, in the name of combating the culture of consumerism where every visual message you receive stems from corporate sponsorship or product placement, the Street Sign Project was born."

Tacoma School of the Arts students recently embarked on their own street sign project, participating in a graffiti course, ("Graffiti 101, history and ethics"), as well as creating a collection of painted cardboard signs that was then installed on a vacant wall downtown. The messages relay the kids' choices. "Make Art not Babies," is by far my favorite, and also ensures childlike giggling will ensue.

One of the newest projects associated with the Street Sign Project is the "outreach street team" - a scavenger hunt that sets contestants on the prowl for other works of guerrilla art. The winner receives a package of art in the mail. But there's a catch: They can't keep their prize. Instead they must install them around their hometown and send photos as proof "(It's) sort of like a 21st century graffiti pen pal program. Chicago was the first (to participate and win), but any city in the world might see SSP items in the streets soon," says the founder, adding, "We encourage all citizens to contribute to the visual language of the streets."

A new addition to the project - aside from the obvious and bold message signs - are cryptic matrixes created from duct tape now flourishing in Tacoma. According to the Facebook page, "These symbols represent ideas and how they spread through communities. The filled and hollow shapes stand for people who either understand or do not understand a concept or philosophy."

Just another interesting facet of a unique and creative phenomenon that started in Tacoma and is now gracing the world - the Street Sign Project.

"The projects are designed to be very anonymous, so it is unclear exactly who did the work," says the Street Sign Project's founder - providing the reason for his anonymity. "This allows anyone that wants to try it to become a part of something much larger than one individual identity."