Well, I've just been to the dentist!
If it wasn't enough that the Coca-Cola company produces a product that can dissolve a dime/your teeth in five seconds flat:
http://www.killercoke.org/
http://worldofwonder.net/archives/art.php
The exhibition described in the second link is on in London this month.
Hardly surprising they've a base in Columbia, given the roots of their product...
Royston
p.s. a two-litre bottle of coke left open for two days then poured down your loo sure shifts that limescale!