ANIMAL CRACKERS XIV - SPIDERWORT

I believe this pretty little flower is spiderwort, and that unfortunate name derives from the web-like filaments around the stamen. Please correct me if you know it as something else.  Some of the spiderwort photos I found look nothing like this vibrant beauty, which is cultivated in a friend's garden. Another article I found stated that they could detect radiation!
[edit 22/10/11 - Tradescantea x andersoniana it is, but all the sites I've trawled list it as spiderwort so it fits my animal crackers series! :)]