Issue these commands:
echo "rpcuser=user" >> /Users/<YOUR USER HERE>/Library/Application\ Support/Bitcoin/bitcoin.conf
echo "rpcpassword=password" >> /Users/<YOUR USER HERE>/Library/Application\ Support/Bitcoin/bitcoin.conf
The above assumes you change <YOUR USER HERE> to your username and that you move the v0.3.24 folder you downloaded to your /Applications folder.
This will also run the GUI, can't be helped without recompiling, but the app will now respond to commands.
Should return your current Bitcoin account balance (assuming the local client is the one you use and has your wallet.dat)