> I can mirror a yahoo group but i was wondering if there 
> was any way to exclude the messages?  They take up the 
> most space and takes the longest to download.

I really don't know yahoogroups, but did you try httrack 
filters ('Set Options'/'Scan rules') ?You can even filter usig rules based on
query strings ; 
such as:

-* +www.example.com/foobar/* +www.example.com/*foo.cgi?q=12&r=*&s=a*&m=23
+*.gif +*.jpg +*.png +*.css +*.js

(the first rule, -*, excludes everything by default ; then, 
accepts everything in the /foobar/ folder, plus foo.cgi 
script with proper parameters, and all associated 
images/style files)