Karen and I went over to see who was on the plinth this lunchtime - and it was a woman throwing yellow paper planes.
One of the best plinth performances I've seen so far, it was very engaging to watch the crowd of people oohing and aahing as the planes caught updraughts and downdraughts, some getting caught in the netting around the plinth. Every paper plane contained a quote or saying. Grown adults as well as children ran to gather one up as a prize, as soon it fell to earth. A party of schoolchildren near us were jumping up and down and screaming with excitement, falling over each other in their eagerness to catch a paper plane... You couldn't help smile, and the "plinthee" got a hearty round of applause when her time was up.
I must admit I am becoming a plinth devotee watching the webcasts between PBase and facebook views ;-)
You know the official company have a group on flickr that links to their own webpage?
http://www.flickr.com/groups/oneandother/pool/