In older versions of OS X, you could use Quick Look to view print jobs in a queue. In Lion, you can now not only view them but also open them -- this is great if you have a print job which did not print for some reason; you can open it in Preview (or other programs) and then save it.
[crarko adds: A handy new feature. The 'Open in Preview' option is a button in the upper right-hand part of the Quick Look window.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110727110459381