Here is a customization to the default command prompt in Mac OS X's Terminal.app. If you add this line

export PS1="\[\e[0;36m\]<\u> <\w> $ \[\e[0m\]"

to your .bash_profile file in your home directory and re-launch terminal, your prompt will appear as follows:

<username> <current working directory> $ 

The prompt will appear in a blue color that looks good against a black background, and your commands will appear in white.