Flickr Images per 100,000 people
Predictably, we see some of the same core-periphery patterns that are observable in other types of user-generated content (e.g. Wikipedia). More surprising is the fact that unlike the geography of Wikipedia content, there are a significant number of low-income countries with relative large amounts of content (i.e. images) per every 100,000 people and 100km. Cambodia, Oman, Namibia, South Africa, Nepal and a host of other countries all score highly using these normalised measures.
I would hypothesise that two factors are at play here. First, there are lower barriers to entry on Flickr versus Wikipedia. In other words, despite the openness of Wikipedia, it is still easier to upload geotagged photos to Flickr than to create a new article and defend it's existence against nominations for deletion and overzealous editors. Moreover, the binary developed vs. developing country division has always masked the range of differences between and within countries, e.g., an interesting comparison between Oman and Yemen.
Second, it is also probable that much of the content in low-income countries is created by visitors and tourists. For instance, a significant number of photos geotagged to Cambodia are likely tourist shots of the Angkor Wat temple complex rather than locally created scenes of more everyday events.
Whatever the reasons are, more research is clearly needed on the topic to uncover what the specific biases in authorship are. Furthermore, irrespective of the specific reasons, it remains that these maps continue to show significant unevenness in user-generated content around the world.
For further reading see:
Graham, M. 2010. Neogeography and the Palimpsests of Place. Tijdschrift voor Economische en Sociale Geografie 101(4): 422-436.
Zook, M. and M. Graham. 2007. The Creative Reconstruction of the Internet: Google and the privatization of cyberspace and DigiPlace. GeoForum 38(6): 1322-1343