A while a go my son introduced me to Guerilla Knitting. If you’ve not heard of it before this is the Wikipedia definition: Yarn bombing, yarnbombing, graffiti knitting or yarnstorming is a type of graffiti or street art that employs colorful displays of knitted or crocheted cloth rather than paint or chalk. …  

Search the web and  you will find examples from all over the world.  Here are some of my favourite:

This was one of the first examples I saw and I still love it.

The 2 pictures below show statues embellished  as part of the Leicester  Comedy Festival back in February 12, when Thomas certainly needed his scarf. There are more pictures on A sewing Odyssey .

This is my favourite example. I just love the colours.