Luke Jerram has created some mind bending largeArt in the past (see his installations page for a some fine examples). His latest work takes the cake IMO.

In the city of Bristol (Pop 500,000) there are on average 11 babies born every day.
First breath celebrates each new life with a searchlight projecting up into the nights [...]

Cuprocking is the brain child of Sydney based artist Andy Uprock. By mapping out large areas of cyclone fencing and sticking plastic cups into the existing diamond shaped holes, Andy transforms streets and public areas into floating walk-by galleries.

I read about some playground jamming on pixelsumo today.
My favourite item was the laughing swing, a device that you attach to a regular swing. When you sit on it, it chuckles. As you swing, it laughs, and the higher you go, the harder it laughs. At the peak swinging it is laughing wildly.
It seems [...]

I’ve always loved the idea of culture jamming with a vending machine. Years ago I read an article about a second hand book vending machine, which I thought I might duplicate on the local university grounds. While researching I came across the artomat, where artists use retired cigarette vending machines to sell small artworks.
Today [...]

A few months ago I read about some amazing sculpture on the Wooster collective blog. The (then-unidentified) artist used plastic bags to create a bear lying over a subway grate. When trains went by the air would inflate the animal and make it look like it was moving. Then I then found a video on [...]

taking the park to the people. This idea goes a step beyond guerrilla benching (reported by space hijackers back in 2006).

This project is a study into different ways of bringing play back into public space. It focuses on ways of incorporating incidental play in the public realm by not so much as having separate play [...]