ActiveWords is a user interface technology for Windows that turns the words you type into actions. For example, if you want to launch Microsoft Excel, you could just type "excel" and hit the default launch button of F8; if you wanted to view the weather forecast, you could just type "weather" and have your favorite weather web page launch. In this way, ActiveWords reminds me of how I use Vista's built-in search feature. I hit the windows button then type what I want to launch. I've become accustomed to launching my favorite programs this way - msword for Microsoft Word, mspaint for Paint (I still use this for screenshots!), mstsc for Remote Desktop, cmd for Command Prompt, etc. But ActiveWords adds on to this ability by allowing you to custom these commands and create your own. For example, you could create an ActiveWord "10" to launch this site!
However, ActiveWords does even more than launching programs - it also can auto-correct your misspellings as you type. Now, your custom dictionary can be available throughout all the applications you use, not just in one program or another.
If you're into efficiency/lifehacks, you should check out ActiveWords. It's not freeware, but you can try it free for 60 days, which is long enough for you to decide whether or not it's right for you.