There is so much great Free Software out there, you just cannot know every tool, application or program worth more than a quick look. But luckily, members of the community centering around GNU/Linux are here to hint you to the real jewels you might have missed otherwise
Let me be one of those friendly fellows today, and introduce you to one of my dearest little helpers, conceived to be run as a part of the K Desktop Environment: Katapult
So what's the fuzz about? What can this Katapult-thingie do for you? Well, a lot of neat things:
Once installed and running, you interact with Katapult by pressing [ALT] + [SPACE] (of course you can remap this binding, according to your personal preference), and start typing...Katapult is an application for KDE, written in C++, designed to allow faster access to applications, bookmarks, and other items. It is plugin-based, so it can launch anything that is has a plugin for. Its display is driven by plugins as well, so its appearance is completely customizable. It was inspired by Quicksilver for OS X.
Say, I hit Katapult's bind, followed by the letters "kon", i'll be presented with a semi-transparent overlay on my desktop, posing "konsole" in its center - once I hit [ENTER], "konsole", KDE's terminal emulator, fires up. This works with programs recorded in your K Menu, directories in your ~, bookmarks in Konqueror, many things in amarok, and - because of Katapult's nature of exentsibility via plug-ins, many, many other things not yet thought of, too.
Well, head over to the KDE-Apps.org page, or, better yet, fetch it from your distro's package manager's repositories to give it a try. I bet you won't regret doing so
PS: You're welcome to present your very favourite program in this topic as well, of course