Describing itself as "a command line for the web," YubNub is an interesting web-based application. Basically, it's a keyword launcher that does (pretty much) whatever you can do within a search box on a web site. For example, instead of going to Google and typing a search string in the box, you just type "g slackorama" in YubNub and it'll run the search for you. There are lots of examples on the site (and more coming in all the time from users). To make things easier, there's a Firefox extension as well as other integration instructions for Safari, Internet Explorer, etc.