Our interface remained only a design until now - however, now we are seeing a growing number of visualizations which measure some social media activity and create rudimentary maps, or simply list trending keywords (for instance, twitter web site itself) - little steps towards a future much richer map which can be actually useful.
A WORLD OF TWEETS project by frogdesign stands out from the rest - the dashboard around visualization offers useful information and you can actually start seeing interesting trends. (It also shows that now that everybody has access to the APIs and data they provide, its good designers who will make better visualizations):
-------------------------------
Countries with the most tweets (Since 1st Nov 2010):
UNITED STATES 38%
INDONESIA 15%
UNITED KINGDOM 10%
BRAZIL 7%
-------------------------------
Patterns observed:
- parts of the US are completely silent
- Europe is fully on (good job!)
- all other clusters of tweet activity are on or relatively close to the ocean coasts
- compare this map to another wold map made from geolocations of 35 million Flickr photos - which all cluster in coastal areas :
(David Crandall, Lars Backstrom, Dan Huttenlocher, Jon Kleinberg. Mapping the World's Photos. WWW 2009):
-------------------------------
More data from A WORLD OF TWEETS:
Top 4 Asian countries are:
INDONESIA 65.26%
JAPAN 10.76%
SOUTH KOREA 6.17%
MALAYSIA 4.96%
-------------------------------
Patterns observed:
While doing research on the global Manga interest using Google Insight (which analyzes the amount of Google searchers for particular keywords), I also noticed that Indonesia and Malaysia were the top countries in the world in terms of number of searches for manga.
The following are the screen grabs from Google Insight:

