Just been in the local Barclays branch and there was a collecting box on the counter for unwanted (old, foreign) coins in support of Childline. I've seen a similar thing in LloydsTSB as well. Couldn't find much on the web about the Barclays/Childline boxes (apart from something from Barclays from 2005). I find these collecting boxes quite useful e.g. when clearing out the bottom of draws etc etc.