Not answeing your question, I know, but it's probably millions of pounds.
But regarding pennies in Jars, our local Sainsbury's has a coin counting machine. You just pour all your coins into a fish-fryer type thing...it counts them all up, spits out any foreign ones, and then prints you out a voucher you can exchange for cash or shopping.
Total genius.
Saves having to spend hours counting coins into little bank bags
I put all of my 1, 2 and 5p coins in a green elephant piggy bank. Last time I emptied it, i only put 1 and 2p in there, and i have about �6. Im hoping for at least �10 next time. We also have another jar downstairs, but no idea how much that has got in. Thinking about it, loads of people I know do the same
When at school I put all change I could find into a [disused] Whisky bottle [One of the large Bells ones] for two years... ended up with more than enough money to pay my contribution to a skiing trip [parents attempt to make me understand the value of money or something!]... seem to remember it was about �60, have always kept then in various containers since. The machines in Sainsbury's take something like 7% of the money put through them as a charge.. far easier to sort them into coin type stick um in those little pastic bags and take them to your bank