I've always wanted an preference pane that would show and hide the dock based on which app is in the foreground. This simple plist hack does the same thing on a per-app basis. To hack an app so that when it's active, the menubar and dock are hidden, you need to find its info.plist file. Control-click on the program in question, choose Show Package Contents from the pop-up menu, and then navigate into the Contents folder.
Once there, add the following to the file:
<key>LSUIPresentationMode</key>
<integer>4</integer>
Be sure that it goes in alphabetical order, otherwise it won't work (i.e. LSUIPresentationMode goes after LSMinimumSystemVersion but before NSAppleScriptEnabled). Save the file and enjoy.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20070118003804854