If you want SharePoint 2007 built-in RSS Reader webpart read your SharePoint content and you get this error message inside the webpart after configuration :
"The RSS webpart does not support authenticated feeds"
then you need to change the authentication method from NTLM to Kerbrous and if you don't want to do that you can install an alternative RSS Reader webparts like the one below to get rid of the error message:
P.S: After some slight changes to the source code, this webpart works greatly in our environment.
