Picture Formats in Microsoft Word

Recently I was "racking my brain" trying to remember how to insert screen shot pictures into Microsoft Word that will scale and print effectively. Word accepts everything from .gif to .jpeg to .tiff, but I feel the best results are achieved when a screen shot is taken using the "print screen" command and then inserted using the "paste special" command as an EMF (enhanced metafile). Doing so will include meta information in the file that will help Word better analyze its properties (i.e. when a graphic is resized) when it comes time to print.

Terminal command in 10.4 to set default screen capture mode:
defaults write com.apple.screencapture type pdf

Here are a few decent articles on the subject:

UC Davis Intranet Site
Windows Metafile FAQ