Open Files from Quick Look to Other Applications
Quick Look in Mac OS X Lion includes a “Open with [Application Name]” button in the upper right corner of the windows, but you’re not limited to launching the file in only that app.
Right-Click on the suggested application name to show a contextual menu where you can select to open the file in another compatible app, this menu is very much like the Finders “Open With” menu that pops up with right-click.
If you’re not familiar with Quick Look, select a file or folder in the OS X Finder and then hit the Spacebar. The resulting window will give you a preview of images, text and pdf documents, and more. Quick Look is also further customizable through third party plugins.