From Jim McGowan:
Do It is a small application to manage categorized to do lists. Each to do item can be linked with a file on your computer, a URL, such as the address of a website, or a contact from your address book. The linked item can be opened directly from the Do It window. Do It items can also include notes, priorities and deadlines, which can be set as reminders in iCal. Do It is applescriptable, includes plugins for Address book, to quickly set contact reminders, and a plugin for Quicksilver to allow rapid creation of Do It items from the Quicksilver interface. You can sync your Do It lists on multiple computers using .Mac.
What's new in this version:
Compatibility with Mac OS X 10.5 (Leopard)