If you are getting something like the following, on a box without ipv6 connectivity:
/opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/excon-0.44.4/lib/excon/socket.rb:291:in `raise_timeout_error': read timeout reached (Excon::Errors::Timeout)
from /opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/excon-0.44.4/lib/excon/socket.rb:49:in `rescue in readline'
[...]
from /opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/fog-core-1.29.0/lib/fog/core/connection.rb:81:in `request'
from /opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/fog-1.28.0/lib/fog/rackspace/service.rb:42:in `request'
from /opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/fog-1.28.0/lib/fog/rackspace/storage.rb:444:in `request'
from /opt/rbenv/versions/1.9.3-p547/lib/ruby/gems/1.9.1/gems/fog-1.28.0/lib/fog/rackspace/requests/storage/put_object.rb:35:in `put_object'