I just went through some bags of old coins in the attic today, and having bagged up all of the coins that are still useful (i.e. UK, US and Euro coins), I'm left with a bunch of obsolete coins (e.g. Dutch Guilders, Austrian Schillings, etc.).

So, rather than just throw them in the bin, I have a question:

Can I donate them to charity, or give them to the bank to be melted down and reminted, or otherwise do something constructive with them?