I confess that the application launcher I use most is [Quicksilver][qs]. Some of Quicksilver’s functionality has been available through Spotlight for years now, but if you have recently upgraded to Lion, then you know that Apple has also introduced a graphical app launcher, [LaunchPad][lp]. LaunchPad is very nice: it is accessible from the Dock and it has readily recognizable functionality precisely because it looks and acts just like iOS. The downside is that, also like iOS, it can get cluttered.
By default, Apple has placed all your installed applications in LaunchPad. One way to clean things up a bit is to pursue the iOS model of stuffing things into the iOS equivalent of folders. Another way is to wipe the slate clean and put exactly those apps you want in the LaunchPad.
**Warning**: *Command line goodness ahead.*
To proceed with the latter course, you will need to open a terminal window in your terminal app of choice — I use the built in Terminal.app — and enter the following on one line:
sqlite3 ~/Library/Application\ Support/Dock/*.db “DELETE from apps; \
DELETE from groups WHERE title<>”; DELETE from items WHERE rowid>2;” \
&& killall Dock
The backslash `\` above simple denotes a line wrap.