The following image is a visual representation of currently observed DNS blocking worldwide. Each column represents a single country, and each row a single domain. Domains are currently chosen both from blacklists published to wikileaks.org, and from alexa top domains.
There are many clearly visible cases of DNS censorship, where a domain is resolvable everywhere except one or two countries. Also interesting are the cases of co-censorship, where we see countries sharing blacklists and censoring the same sets of domains.
Per-country maps of observed censorship are likely more interesting. We have generated these maps from pre-processed data, and are in the process of converting unblock measured censorship into this format as well.