With recent builds of Fiddler, it’s been fun to see how many sites have HTTP spec violations and of what kind. As a tool, it’s helped me track down some corner case problems in our own product at work. 
Today’s selection comes from amazon by way of imdb – a simple request tracker hit:
The offending entry
The request (fun user agent, eh?)
GET /e/ir?t=internetmoviedat&l=as2&o=1 HTTP/1.1
Accept: */*
Referer: http://us.imdb.com/name/nm0904140/
Accept-Language: en-us
UA-CPU: x86
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SV1; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.0.04506; .NET CLR 1.1.4322; .NET CLR 3.0.04320)
Proxy-Connection: Keep-Alive
Host: www.assoc-amazon.com
The response is just the typical 1-pixel gif image:
% wget -q -O foo.gif ‘http://www.assoc-amazon.com/e/ir?t=internetmoviedat&l=as2&o=1′
% file foo.gif
foo.gif: GIF image data, version 89a, 1 x 1
