How do I set my Terminal / shell PS1 prompt?

The problem with your "cat" command is that, generally, if the file has Windows' CRLF line endings, it will still look fine. Most Unix systems I use have a "-v" flag to cat which will show any control characters (aside from the newline) as caret-letter. So, if the example .bash_profile were in Windows format, using the command:

cat -v ~/.bash_profile

you would see:

export PS1='mac> '^M

Hi, I'm having the same problem with my command prompt, but my cat -v output appears to be ok with every line ending in ^M:

$cat -v ~/.bash_profile
export PS1="[\t] \w\n\u@\h\$ "^M
export CLICOLOR=1^M
export LSCOLORS=ExFxCxDxBxegedebegacab^M

What am I missing?

As Ken said, you don't want to have those ^M sequences. That's the problem. :-)

"tools that understand the Linux environment lurking underneath your Mac OS X world."

Dave, please print a correction here. There is no Linux environment under OS X. It's a Unix environment. Linux is a Unix-Like operating system. The above information has the potential to send unknowing users to Linux help sites and publications for their Mac, only to find out that the tools on a Linux distro may differ greatly from those on OS X. OS X is closer to BSD Unix, and even that's not a perfect match.

Again, please correct this for the sake of your readership.

Fair observation, Dan. I should probably say "Linux-like" since it's actually quite complicated to figure out the family tree and heritage of any given *nix.

The point of it was, though, that if you were to pick up a Linux book and/or visit some Linux help sites, you'd be able to glean quite a bit about how to work with Mac OS X on the command line. It's that Posix compliance bit and it's having the same shell and same basic commands.