A tree in Baltimore recently was bestowed with its sweater for the colder months. Local knitters constructed a garment specifically for the tree, with the only restriction being that they had to use white, green, and purple yarn. The latest sweater replaces last year's style, which was removed for the dog days.
"We actually made a little bikini for it for the summer, but it fell apart."
The sweater tree is an example of a growing urban phenomenon called yarn bombing, aka yarnstorming or graffiti knitting. Yarn bombing is believed to have its roots in Texas, where it was invented as a way for knitters to creatively utilize their unfinished knitting projects. Common targets are telephone poles, trees, and banisters, but in Mexico City, yarn bombers aimed their knitting needles at a more ambitious endeavor: a yarn-covered bus.
Update: It appears that yarnbombing has reached the streets of Dunsborough, a fairly rural area of Western Australia. Wrapped, a collective of knitters between the ages of 8 and 87, has taken over the streets with their purled pieces. In September, the group got together and crafted wraps, pom-poms, and finger knittings that are being placed on signs, trees, and poles by a group of "knitting taggers" during the month of October. Their goal is to promote knitting events in the area, and to make a difference in the community by spreading woolly good will. The sweater swaths have tags affixed that direct the viewer to their website where they outline the project.
(thx dave)