Tony Ruscoe, an always observant and fearless code spelunker, has found some entertaining easter eggs hidden in the new Google Personalized Homepage themes.
Each of the hidden images show up at exactly 3:14 AM each day for all but the "bus stop" theme.
To monitor the code that makes these themes tick, you can keep your eyes on these files. They are XML documents that describe the different CSS files used in each theme:
Here are some small samples from each theme that show the hidden images in each:
[Images taken from Tony's excellent blog]