Earlier this month I took with me to LHR all of the currency from the Euro countries I do NOT plan to visit prior to 28 Feb 02. I turned them in at a currency exchange for GBP. I kept the non-Euro country notes.
I was afraid that these exchanges may not be willing to do this after 1 Jan 02. When I go back to the first Euro country after that date, I will pick up a supply of the new notes.