It's been fairly well covered that you can drag a file or directory into a terminal window to auto-type its path, but I haven't seen the corollary mentioned:
You can open a Finder window for the current working directory by entering open .
You can also open a window for the containing directory with
open ..
It's a very handy way to get at hidden files and paths without making them visible in the GUI.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20010412034533102