Quicksilver (QS) is so powerful and can do so many things it is almost impossible to list them all! Also because this is in a constant Beta state there is constant improvements and changes.
A really cool feature that you can do with QS has to do with iTunes notifications. When listening to iTunes you can get pop up notifications, but these are not like the growl notifications.
Go to the preferences. Click "Monitor Recent Tracks", and then "Display Track Notifications". Check "Show Artwork" as well if you’ve got some, as it’s nice to have the album artwork pop up with the track name.
The Safari plug-in is great for searching your bookmarks, it has added power for those that can’t live without a web browser open at all times. You may have noticed from checking out the catalog, there’s an option in the Safari module to add the Safari History to your catalog.
if you add the history to your bookmarks, you have a catalog with every web page you’ve bookmarked or at least found interesting enough to visit over the last several days and are still in your history.
Now QS doesn’t search the full text of the content of the web pages, but you’re getting a very quick title-based search of all those pages. Safari doesn’t have a built-in combined search for either bookmarks or history. Also, this sure beats scrolling through your history sub-menus trying to find that one page you were at a few days ago. You can also use the right arrow after selecting a web object to link surf.
Personally I have disabled both bookmarks and history for my searches. To me it speeds up my searches and is a little more accurate. As I have said before you can enable switch to text mode if no match is found under Preferences > Command and then just start typing in a web site name and then you will notice that the action field (the second window) changes to Open URL. Hit Enter and a new window opens up! fast and nice. Now you dont have to open up a minimized window and type Command N to open up a new window, you can just do it all from Quicksilver.