https://bitnodes.21.co is a very interesting site that shows all the bitcoin nodes around the world in real time. Bitcoin nodes are individuals and companies that support the bitcoin peer to peer network.
Without these nodes, there would be no bitcoin network. The bulk of the nodes are in Europe and the east coast of the US. Note that these nodes should not be confused with miners. Nodes help support the network by validating and relaying transactions. Miners confirm transactions and place it on the blockchain. There is a subtle but important difference.
As of this post, there are 5575 nodes in operation around the world with the US and Germany leading the way.
If you are interested in helping to support the network, all you need is a computer, some software and an internet connection.
A raspberry pi is ideal because it is small, consumes very little power and can be left running 24 x7.
