It took me awhile to figure it out too. Mostly it's a means of competing without really competing head-to-head, by playing against the AI at whatever level you choose, with whatever options you choose, then posting your scores to the Metaverse.
A lot of people join Empires, which is another way of competing, since the Empire's get rated by various criteria as well. A lot of people are having a lot of fun! Some of the different Empires have active members in the Forums as well, and I've seen some pretty hilarious puns, pictures, and other humor in a few threads.
Start a game by selecting Metaverse on the opening menu of the game, log in, and click play. That game will be a Metaverse game which you can choose to submit or not, save and play again later on as time permits, like a normal game. The catch is you have to log in to start a Metaverse game, or else it cannot be posted for a score. Here's some links for ya:
Metaverse homeMetaverse top scoresAnd musn't forget the AltMeta, which uses a slightly different scoring system -
ALTMETAWe need some new guys, the stuffed shirts with the high scores are soooo boring.

Hope you have as much fun as I have.
