Steve at InsertTitleBlog.com has produced three screencasts 
which walk through various things you can do with Quicksilver , which is as Steve says, “an extremely powerful productivity app for Mac OS X”.
Quicksilver gets a lot of good press in the blogosphere and deservedly so. However, it is not always easy to work out how to use it to its full potential, which is either a charming part of its mystery or frustrating, depending on the kind of person you are.
The first one is an overview of the app that provides a demonstration of how it works and covers installation and set-up.
The second one shows you how to navigate files and folders, how to move and delete files with Quicksilver, how to send attachments and emails through Mail.app and how to use Quicksilver to append text to files.
The third covers using the clipboard and shelf and how to set up triggers, including a trigger to email the currently selected item (file, image, whatever).
If Mail hadn’t already made me deliriously happy, Quicksilver would. It’s my second favourite Mac app.
These videos repay the time it takes to watch them. Old timers may pick up a trick or two; newcomers will find these screencasts an excellent way in.
The screencasts are no longer at InsertTitleBlog.com. They can be found at: http://www.youtube.com/watch?v=EBvFUhTqKK4