GitHub exposes public ssh keys for its users
thechangelog.com
thechangelog.com
Does Github just want us to use the API Method? http://developer.github.com/v3/users/keys/#list-public-keys-...
ruby -e 'require "json"; require "open-uri"; JSON.parse(open("https://api.github.com/users/<username>/keys).read).each{|x|puts x["key"]}'
Maybe there's something about the .keys URL possibly going away or moving, while the API is pretty much guaranteed to be there for as long as that version of the API works.