Shapeshifter v2.2 - Lets you use themes on your computer; you can customise theme, iconset, curserset (if you have mightymouse installed), and wallpaper. Opens .gui files
MightyMouse v1.2.2 - Lets you change the theme of you cursors. Some shapeshifter themes come with cursorsets that match the GUI.
ClearDock v1.3 - Makes the background of the dock clear or changes dock/application triangle color.
Konfabulator v? - Lets you run widgets. Similar to dashboard but has been around longer and can run in operating systems older than Tiger.
Amnesty Widget Browser v.? - Lets you run Tiger dashboard widgets in Panther or earlier
LaunchBar - Quickly search through places such as your Safari history or you computer by pressing cmd+space and then typing a short description of what you want
KONFABULATOR WIDGETS
Gir_Desktop! - puts Gir from the Nickelodian show Invader Zim on your screen. Double click to hear a quote.
iChat Bezal - tells you when a user signs off or on in the form of a bezal
iChat Patroller - puts a small list of people in your buddy list on the side of the screen and a green, grey, or red bubble to indicate thier status.