How to remove an app stuck in "waiting" mode from the Mac App Store? I've got 2 applications that I installed via the Mac App Store that are still in the "waiting" mode. How do I get these applications to finish installing? Or how do I remove them and try again?

By "waiting" mode I mean they are showing a download progress bar and have the word "waiting" overlaid their icons inside of the launchpad app. (I would take a picture but it doesn't seem to let me while showing the launchpad)
I had a problem with not being able to stop an old OS from downloading. In order to delete it and stop the download, once opening launchpad, I held down the 'option' on my keyboard which caused the apps to wiggle just like on the iphone. I could then click the 'x' and delete them/stop the download.