This has already been blogged quite a few times by people, however I regularly have to google how to Show hidden files on Mac OS every time I re-build my Mac or buy a new one.
Thanks to OSXDaily for the original information.
Show Hidden Files on Mac OS X
Launch terminal
defaults write com.apple.Finder AppleShowAllFiles TRUE
killall Finder
Make sure you restart the finder by doing the killall command.
If you want to hide the files again, follow these instructions:
defaults write com.apple.Finder AppleShowAllFiles FALSE
killall Finder
Not much too it, just wish I could remember the command!
Nice article, gotta love command line1.
You can also do this using a killer tool that allows you to toggle between hidden and viewable files from the Mac menu bar. Lovely app and free w/ source if you are so inclined.
http://stevenwright.github.com/Bifocals/