Source: How to reset and manage the OS X 10.7 Launchpad interface | MacFixIt — CNET Reviews.

Kessler:

By default Launchpad will show all of your installed applications, and if you click and hold one application they will all go into the familiar iOS “wiggle” mode in which you can then drag them into groups and move them around as you see fit. While you might enjoy doing this on a new system, if you have a number of applications already installed on a system that you have upgraded to Lion, then you may experience a certain level of frustration in dealing with pages and pages of application icons, especially if you have multiple Parallels Desktop virtual machines installed.

If you are experiencing these frustrations with Launchpad and still wish to use the feature, then one approach you might consider is to clear out Launchpad and start it over from scratch, to organize as you see fit.

As for me, I still haven’t upgraded to Lion, but from what I’ve seen of the Launchpad so far, I can safely say it’s a nice idea, but I don’t think I’ll use it at all.