"We apologize the site [Flickr.com] you are attempting to visit has been blocked due to its content being inconsistent with the religious, cultural, political and moral values of the United Arab Emirates."
That's the message you're likely to see when trying to access Flickr pictures from certain gulf countries like UAE and Iran because the administration has blocked the photo sharing site from citizens for various cultural and religious reasons.
[The government ban also applies to sites like Hi5, Friendster, Skype, etc.]
To unblock Flickr in UAE, Iran, China or any other country, you may try the standard proxy route but there's a much better option developed by an Iranian photographer who's an ardent Flickr fan himself.
Hamed Saber has released an Access Flickr extension for Firefox that will let you circumvent the internet filters of any country where the site is banned.
The Access Flickr extension for Firefox substitutes the HTTP header parameters before sending a request to Flickr and therefore fools the government filters. This extension is only for accessing Flickr.com, it won't work for other sites like YouTube or Orkut.
Download Access Flickr | Hamed Saber on Flickr
More articles on defeating Internet Censorship:
How to Access Blocked Websites
Access Bebo, MySpace, Orkut, Hi5 at School or Office