"One Minute Sculptures" by Erwin Wurm

I saw (and loved) these photos in a show in Madrid called "Between Times: Instants, intervals, durations", which was part of PhotoEspana:

I've recently discovered that in some circumstances the work is also shown in an interactive way:

"Visitors can become objects of art by holding a variety of household items in Erwin Wurm's One Minute Sculptures (2006)... These works suggest that "participation" is when art and audience are in a symbiotic relationship, mutually calling each other into being and giving each other purpose. And it cannot be an audience of just one; there has to be a crowd/collective/community for the works to find form."
(quote from here) 

Here is a gallery shot of an interactive exhibition:

I spoke to a friend who saw this interactive version of the show and she said people actually did participate (I was skeptical, thinking that people might be shy). She said they were nervous at first, having to step on the pedestal and become the art, but all it took was for one person to grab an object and do something silly, and then everyone else followed suit. Erwin Wurm is now my hero.