Mobile QuickSilver-like User Interfaces

"Tom Hume pointed out an app called Qix which is essentially QuickSilver for your Series 60 phone. Until I got my Mini, I had no idea what exactly QuickSilver did, but now I can't live without it and I get frustrated when I'm on my work PC and have to hunt around for apps and docs. In case you don't know either, QuickSilver is this program running in the background which you call up by hitting control-spacebar (or whatever combo you want) and then you start typing the name of the application, document, link, etc. and a list of items that match that name come up and you can quickly choose that item to launch it. It's very useful. "