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.
There's another company called MotionBridge that's doing something similar in the search space. They've even added an iPod-like hierarchical view of the data as well. I definitely love that way of looking at my data. I don't know about everyone, but I think in hierarchies, so being able to drill down to me is great.
I think this stuff, and the pop-up helpers on the web made popular by Google Suggest, is very cool. It's taking a new look at user interfaces and figuring out what people want to get done, rather than forcing real-world analogies on top of the interface. And all this of course, goes back to the Ask and Ye Shall Receive post I wrote a week or so ago. If you know what you want, just ask for it (i.e. start typing it) and then get it.
This is especially important in the mobile space as the size of the data you store on your mobile is going to increase much faster than the screen size which is physically limited. Being able to just type what you want like in the example above and work through several gigs of data is exactly what's needed. The S60 address book works similarly if you want to test it, just start typing a name and it'll filter out matches.
Really what search and these types of predictive user interfaces do is allow people to easily work with abundance of data, and I find that exciting. I hope these UIs hit the mainstream soon.