Access hidden folders on Mac OS X

As of Mac OS X Lion, Apple made a number of changes to the visibility of various folders, most notably the /Library folder.
 
For a number of troubleshooting tasks, you may need to access these folders, and luckily, there is a fairly simple way of achieving this. Simply use the hotkey commbination Cmd+Shift+G, then enter the path you want, e.g. /var/db/receipts: