file permissions umask?

["Mike Egglestone" <Mike_Egglestone@fc.schdist57.bc.ca>]

Hi all...
I've been working all day on this one and can't figure it out....
maybe you can help...

say I have a folder like so......
/var/www/

I want to set the permissions so that the "owner" and "group" have 
read, write, execute rights to /var/www  (all the time)
I want "other" to just have read and excute.....
I'm not sure how to set this so that when either the "owner" OR a "group"
member writes a file... or edits a file in /var/www/ ........the
permission stay
as 775.......
Am I making any sense?
Currently,  when the "owner" goes in there... they create a file...
and the permissions are set to this.....
-rw-r--r--
but... I want it to more like this....
-rwxrwxr-x

How do I set the /var/www directory (Recursively) so that no matter who
creates or
edits a file... will create the file with these permissions...  775

thanks for your help...

Mike