The ReTweet is, in terms of a growing number of indexing sites like Topsy, the equivalent of an upmod vote or endorsement of the post as has been practiced by Digg or Reddit: basically, if one prepends "RT" to the prior poster’s username, the content of the repost and the associated shortened URL to the external site, Topsy interprets the RT as an endorsement of the reposted content and the full URL. 

So the "DeTweet" was introduced as a concept by various posters as being the opposite of the ReTweet last year, one that has not yet been credibly created or fleshed out for mass consumption or indexer use. Basically, instead of "RT" next to an associated post, a DT would be prepended in order to indicate dislike.

But what does that mean? How can DeTweets be rendered on one’s page, as I’m certain that a DeTweeted post would not show up or be indicated in the same manner as a ReTweet? 

• Perhaps a DeTweet would end up in a different, unique tab on the deTweeter’s userpage than the main timeline of posts and ReTweets?
• Or a different shade of color would cover the DeTweet in addition to it being decorated with a red-colored arrow symbol replacing the green-colored "ReTweeted" arrow symbol that shows up in a ReTweet?
• And let’s not forget that Topsy could easily detect DeTweets, although comparing DeTweets to ReTweets would be more along the lines of measuring instances rather than percentages, as there wouldn’t be a likely means by which a user’s DT or RT could be accurately limited to one exclusive vote in either direction.
• RT/DT could be further honed into bite-sized prepended acronyms such as LOL, OMG, EWW that would be similar to Hashtags in being linked and prepended with a symbol indicating separation from more custom interjection or comment, except that these emotihashtags (for lack of a better term) would be measured alongside hashtags and posts in order to aggregate the current feeling or emotion of Twitter users regarding a topic. This would ultimately be a useful function of indexing sites like Topsy, and it would help viewers to aggregate the often-untranslatable, often-cerebral connotations of emotions that are reflected in such opinions.

Furthermore, the design of a DeTweeting interface would further invigorate the debate over sharing bite-sized personal opinions alongside upvotes or downvotes, something which Buzzfeed and Topix already do. 

It wouldn’t necessarily be a matter of direct e-polling democracy unless the DT/RT function could be further perfected toward that end, but I think it makes sense to allow further interjection and aggregation of current and past user emotion and opinion.