You know some enterprising young gal will one day get the first QR code tramp-stamp tattoo.
...funnily enough, I am actually planning on getting a QR code tattoo. :p My tramp stamp is actually
this, and I want a QR code tattoo to contain my business card information (I am always forgetting the damn things and they are hardly environmentally friendly!). For that reason I'll probably get it on the inside of my wrist (which will hurt like hell :/)
As for this use of Bitcoin, I've been surprised it has not happened sooner tbh! Ideal for your modern discrete "personal services" clientèle.
Kate.