This one actually got printed on MacOSXHints. The Mac has always had an easy way to trace back to the original file of an alias. Select the alias in the Finder and choose 'Show Original' from the File menu (or just hit Command-R), and the Finder will highlight the original file. What I did not realize until recently is that this functionality also extends to multiple files.
So, if you have aliases to several files, say, in a Burn Folder, and you click 'Show Original,' the Finder will highlight all the original files. If the original files are in the same folder, they will all be highlighted in one window. If they reside in different folders, each of these folders will open in a new window with the original items highlighted. This saves a lot of time and brainpower if you want to label — or perform any action — on multiple files in your Burn Folder, or any other folder full of aliases.
Maybe this was obvious to most people, but it was certainly a pleasant surprise to me.