Hitting the Quicksilver hot key combo brings up this window which shows the top match on the left and the available actions on the right (launch is the default)

As I've played more with Quicksilver, I've come to the conclusion that if you didn't know about command line terminals and you sat down to design a CLI for a GUI-based machine, Quicksilver's what you'd come up with. At first blush, Quicksilver is a launcher, but its much more than that. It has an adaptive search that targets almost any data source you can think of. What's more, it has a nice plug-in architecture that let's users extend it to apps that might not otherwise get integrated. Some small examples: hitting the hot key and typing "ksl w" let's me launch the KSL Weather page in Firefox. Typing the start of a contact's names brings up their contact information and let's me act on it. I can even select songs to play in iTunes from the keyboard.

One of my personal productivity goals is to reduce the number of times I take my hands off the keyboard and Quicksilver is a big part of making that goal happen. Here are a few resources I've found helpful: