An upgrade to this Utility has just been posted so I wanted to discuss it a little, show some screen grabs and let you have at it
You can modify the Apple settings in Preferences and in the Systems Preferences panes but there are many settings that are not available. Previously, you had to use the terminal or Unix Command line to make many of these changes. With Tinkertool you get it all in a GUI (Graphic User Interface)
Here are General setting that you can tweak in the Tinkertool General Tab.
Again here are Safari settings
The program is available at
http://www.bresink.com/osx/TinkerTool.html
And there is a way to set all to defaults if you want to revert to original setting
Great Utility for those who have the need and interest.