gistfile1.js

var helloEthereum = 'contract testContract {    function go() constant returns (string) {        return "ETHEREUM!";    }}'

var helloEthereumCompiled = web3.eth.compile.solidity(helloEthereum)

var ethereumContract = web3.eth.contract(helloEthereumCompiled.testContract.info.abiDefinition);

var ethereum = ethereumContract.new(null, {from:eth.coinbase, data: helloEthereumCompiled.testContract.code, gas: 34000}, function(e, contract){
    if(!e) {
      if(!contract.address) {
        console.log("Contract transaction send: TransactionHash: " + contract.transactionHash + " waiting to be mined...");
      } else {
        console.log("Contract mined! Address: " + contract.address);
        console.log(contract);
      }
    } else {
       console.log("error");
       console.log(e);
    }
})