7 of 20 changed link to Picasa album for quicker link to photo

Eldarerathis summarized it very well. To add some things: The 1.1 version was internally called Petit Four by Google, and that's how it all began. Google is installing a giant pastry on their lawn at Mountain View each time a new version is about to be launched.

You can see pictures of that display at different stages here:

Overall display (Cupcake to Eclair, with Petit Four tribute)

Overall display (Cupcake to Eclair, with Nexus One)

Honeycomb

Eclair, Froyo, Gingerbread, Honeycomb and Ice Cream Sandwich

Gingerbread, Honeycomb, Ice Cream Sandwich and Jelly Bean