apache configuration, relax Auth restriction on 1 file?

[Alex Dean]

I have a site which requires HTTP authentication.  There is 1 script  
I would like to allow anyone to access, even if they don't have  
access to the site in general.

Are there directives I can use to turn off HTTP authentication?  I  
don't want to have to explicitly list all the directories on the site  
except for the 1 script I want to leave open.

Seems like it would be ideal to do 1 restrictive <Directory> block  
for the entire site, with AuthType, Require, etc...  and then to add  
another <Files> block with something like 'AuthType none', but I  
don't see that 'none' is a valid option.  Any other way to do this?

thanks,
alex
.