Many Tricks

Free
This program lets you round the corners of your screen.
Free
This app displays a curtain or image on top of your Desktop icons and apps.
Free
Moom is a window management program designed for Mac.
Free
Keymo lets you control the mouse pointer with the keyboard, enabling you to click, scroll, and find the mouse's location without a mouse.
Free
Pops up the front most app's menus at the current mouse location.
Free
App that makes the Mac OS X menu bar opaque and more customizable, allowing users to adjust the tint when their mouse hovers over it.
Free
Services menu in Mac OS X lets you perform actions on current selection, such as opening URL, sending snippets, and more.
Free
Offers you an easy way to change display settings.
Free
Offers you time-saving solutions to help you complete your daily tasks.
Free
Take control of the mouse pointer via the keyboard.
Free
Switch between windows or programs with customized options.
Free
Enter Name Mangler, which makes short work of all your file renaming tasks.
Free
Perform simple and advanced renaming actions.
Free
This tool lets you edit the list of file types that an application can open.
Free
Quickly rename dozens of your files with minimum effort.
Free
Command-S is slated to become useless with the release of Mac OS X Lion and its Auto Save feature.
Free
A program for monitoring how you spend your time on Mac.
Free
Leech is a simple and powerful download manager designed for Mac.
Free
Adds a contextual menu to webpages on vBulletin forums that lets you open all unread article links i
Free
Fixes websites that disable command-click to open a new tab.