\http://www.pollingreport.com/iran.htm
you can "escape" it but apparently the backslash would be visible and selectable. Oh but I think sites that block urls are going to block any string that has a url as a substring. So I don't think there is a way to post a url that can be copy and pasted.
You can try making it look like a url but with spaces or underscores. Or you can refer them to search a google query that returns the site as top result. But honestly I think most people are not going to bother with such methods and it won't boost the target site in search results.