Flickr DNS Issues...

FlickrBlog Flickr Unavailable Flickr has been only sporadically available since Sunday morning and was completely off the map for about 5 hours. You may still be experiencing difficulty accessing the site — if you are, try going through www1.flickr.com, www2.flickr.com, www3.flickr.com or www4.flickr.com.

Looks like you can still get to it from the alternative sites...