In case you don't know, QuickSilver is a popular app launcher for the Mac OS X that enables you to open programs and files with just some quick keystrokes. Now you can have the same functionality in tour PC with MightyBox.
This small app is developed in Java and doesn't require installation. It remains in your system tray, running silently in the background until you trigger it with the Ctrl+Spacebar hotkey. Then you have plenty of options available at your fingertips: open a document, launch an application, move or copy files, browse the folder structure, even write a short note and save it as a text file.
All these options are accessible via hotkeys, which makes MightyBox a must-have for keyboard junkies. These hotkeys are apparently not customizable, or at least I couldn't find a settings window where to change them. Also, it might take a while until you learn how to manage it properly, as it feels quite confusing at the beginning. I personally recommend reading the Basic Use Instructions before giving up on it.
Once you get over the learning curve, MightyBox becomes a truly handy application for your daily work with the computer.