www-data permissions on /var/www

[thufir]

My /var/www directory permissions are:

drwxr-xr-x  2 root root     4096 Nov 11 15:34 www/


While running the install script for FUDForum, I get this message:

Directory "/var/www/" exists, but the installation script is unable to 
write to the directory. Please grant read/write permissions to the web-
server user (www-data/www-data)


The web-server user is www-data?  I tried changing permissions for the /
var/www folder to add group permissions with chmod g+w /var/www but was 
insuficient.

thufir at dur:~$ cat /etc/passwd | grep www
www-data:x:33:33:www-data:/var/www:/bin/sh
thufir at dur:~$ 

thufir at dur:~$ cat /etc/group | grep www
www-data:x:33:
thufir at dur:~$ 



maybe www-data is in the wrong group?  Or, just go ahead and give 
everyone rw permissions to /var/www ?

I'm not well versed in apache.



thanks,

Thufir