[quickthrower2]

How about having some students be the nodes

Their job is to write down the transactions on a piece of paper.

Then have some students be miners.

They write down unconfirmed transactions and roll 2 dice. If they get a pair of 1's they can create a block and give it to the node students to copy. (Could use a photocopier to speed things up)

Then have some students be users creating transactions and such like.

[Jtsummers]

Use physical objects like game tokens and a tray to represent blocks. Faster than handwriting or photocopying. Simple playing cards can also work (this "block" has 4 transactions, the AH, 2S, 3C, 10H).

Someone shuffles a handful of decks together, this creates the feed of transactions going into the network. "Blocks" are created by grabbing a random set of recent open transactions and rolling dice, like you suggest. Pair of ones and that "block" can be passed on to all the other nodes. Others can continue "mining" if they want and try to create a fork, other miners may choose to base their work on the newest block.

Have some sorted stacks of cards or tokens available to quickly assemble copies of the blocks and transactions.

[foopod]

I really like this approach. I like too include physical interactions in all the facilitation that I do, it makes the concept super clear.

Try to cover all the possible scenarios when you are planning it out, what happens when multiple miners create a block at nearly the same time?

Be sure to grab a few friends and test it out first, try to predict what kind of questions people might ask.

Good Luck!