Not sure if you are already aware of an virtual Easter Egg in Google reader. Mainly virtual Easter Eggs within a media is usually an inside joke. Most software developers include a Easter Egg in their software. This is used to sometimes display a joke, an image or even credits.
Easter Egg Mode in Google Reader
To activate the Easter Egg when you are at Google Reader press the keys in the following order.
Up, UP, Down, Down, Left, Right, Left, Right, B, A
Another thing about this mode is that the ‘Like’ button turns into heart shape. And when you click it multiple hearts show up. If you change it to unlike, two parts of a broken hearts animation is show. 🙂
PS: Thanks to Dyanesh for bringing it to my notice, the series of keys to be pressed is called Konami Code.