I fear the proliferation of maps of tweets is in part fueled by the data availability. This week several maps crossed my desktop; all prompted me to ask that vital set of geographic questions: What is where? Why? So what?
Topography of Tweets Map
Local and Tourists
Data artist Eric Fischer worked with the Gnip team using MapBox tools and Twitter data from Gnip, to create an interactive map of local vs. tourist tweets.
The folks at Floating Sheep collected all geocoded tweets from June 25th and 26th that contained the text "standwithwendy" (related to Texas Sen. Wendy Davis' filibuster), resulting in a dataset of 3,702 tweets. They not only mapped them, but explored the timeline of their growth.