If you have Photoshop CS5 and do real estate photography you should know about how to use the puppet warp feature to straighten walls in architectural photos.
Thanks to Jeff for sending me this video! I'd never paid much attention to puppet warp but it is a really cool feature. Note that this feature was new in CS5 so it's not available in older versions of Photoshop or Photoshop Elements. It's one of those awesome features that you get for the extra money you pay for CS5.
This is indeed a hidden gem! Thanks Jeff!