A GoMeme is a specially modified piece of content that spreads virally along social relationships in a manner that benefits every site that helps it spread. Any piece of content can be transformed into a GoMeme.
A GoMeme adds some special information to the end of any piece of content. This information (called a "Path List") shows the sequence of sites that a piece of content has traveled through to reach the site it appears on. Everyone who posts the content adds their site to the Path List at the end. So as the content is syndicated from site to site the Path List grows, and each site in the path thus includes links back to every site before them in the path. As well as being useful and interesting, the Path List has the added benefit of increasing the visibility and search engine rankings of sites in the Path List -- because as more sites link to a site about a topic, that site is considered more relevant on that topic by search engine ranking algorithms.
A GoMeme functions as a "trackback multiplier" -- It makes your site part of the path for a piece of content, wherever it goes after your site. This gets you trackbacks not just from the sites that get the posting directly from you, but also from the parties who then get it from them, and so on.
It could be thought of as a mind-virus that can be attached to any piece of content. It makes the content spread more contagiously, by benefitting those blogs that help it spread further. And in turn, this benefits your blog by getting you more visibility for your blog in proportion to the number of blogs that get a piece of content from you -- which is your reward for finding and promoting the GoMeme. Everybody wins.
Basically we are experimenting to see which kinds of conceptual motivations spread memes best. The first test was a survey which was purely altruistic. The second was survey with a selfish motivation -- a path list so the participant benefits. The third used a humorous article as the host for the meme. The last one in the experiment used a "cause" as the host of the meme. Which one will be the most viral? It's also an experiment in the concept of a path list -- which helps blog authors see the extended upstream and downstream paths for things they post or find on their blogs.
Go here to see an example GoMeme and participate in it.
Here is a more detailed FAQ.