We called them thongs too...until thong underwear made it's debut. Now the the young folk look at you like you're a pervert when you slip up and call flip flops by that name.
This morning I downloaded a new online editing software called "FotoFlex" and experimented with it on a picture of myself, then loaded the result into "Smart Photo Editor" and fiddled with it some more...this is how it finally turned out. I call it "The Flying Nun meets Silence of the Lambs"