We use Amazon EC2 for some of our video processing, below is the most recent Amazon IP range posted (Nov 2008) with the disclaimer that these ranges are flexible and can change at anytime without warning See http://developer.amazonwebservices.com/connect/message.jspa?messageID=107770 for more details:
216.182.224.0/20 (216.182.224.0 - 216.182.239.255)
72.44.32.0/19 (72.44.32.0 - 72.44.63.255)
67.202.0.0/18 (67.202.0.0 - 67.202.63.255)
75.101.128.0/17 (75.101.128.0 - 75.101.255.255)
174.129.0.0/16 (174.129.0.0 - 174.129.255.255)
Also please include the following IPs from our Rackspace Cloud Servers integration:
204.232.192.*
204.232.193.*
204.232.198.*
204.232.199.*
174.143.153.*
174.143.154.*
174.143.155.*
174.143.156.*
174.143.157.*
174.143.158.*
174.143.159.*