You don't really need a dummy plug. just use linux. linuxcoin is one option to search for (it's a bootcd), or you can install linux of your choice and add a miner & bitcoin client.
Actually a miner isn't strictly necessary unless you're actively using your wallet (sending & receiving coin), but letting it run does help everyone, because it processes spent coin. You'll need to make sure you're running the latest version of the client.