I’m not sure why this command doesn’t get more play, so I’m gonna put it out there so google picks it up. At least in Snow Leopard, simply hitting cmd-shift-. will show hidden files for that browse session.
defaults write com.apple.finder AppleShowAllFiles TRUE
At least for me, that’s a much more usable solution than permanently showing all hidden files, which is what you get by executing the more commonly documented solution: