According to a conversation I overheard in Tesco at lunch. It went a lot like this:

Checkout lady: They're getting rid of all these fivers soon.
Man buying sandwich: What's that?
CL: All these notes. They're going to get rid of them.
MBS: Why?
CL: They can't get the fibres apparently. First the fivers will go, then tenners, then twenties.
MBS: What, and we'll use coins instead?
CL: Yeah. Imagine carrying a hundred quid around with twenty pound coins.
MBS: When's all this?
CL: Fivers next year, tenners the year after.
MBS: (Getting a bit upset) That's ridiculous. They're turning us into women carrying purses.
CL: I know! Still, I can understand it if they can't get the fibres.

I don't trust the source, but is there any basis for what this woman was saying? Because she must have got it from somewhere, unless she's completely mad or was just trolling this dude for kicks.