Good answer above from blockchain.info but if you want to do it yourself, then you simply need to understand that your wallet is the privatekey.

Whether you choose to have that privatekey online with a 3rd party; in your computer; on your phone; on paper; or in your brain; or even in your brain as something that can be translated back into the privatekey, that is all it is. The public key is then trivial to derive from the private key. The balance then is simply the sum of all transactions.

So if you're running a client in Linux you can dump the private key and do whatever you want with it. So long as it's meaningful to you - make art if you want.

When you want it you import it, you simply need that string that is the private key.

Probably that's very similar for other operating systems interaction with their clients too.
Other daemon calls listed in the --help and at https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_calls_list


The only complex factor here is that getting the privatekey from the publickey is orders of magnitude more difficult.