I just installed Fedora 16 (yea, I know it's old and not supported but, I had the CD burnt :) )
Anyway, coming to the solution, this is what I was required to do:
su -
gedit /etc/phpMyAdmin/config.inc.php
if not found... try phpmyadmin - all small caps.
gedit /etc/phpmyadmin/config.inc.php
Locate
$cfg['Servers'][$i]['AllowNoPassword']
and set it to:
$cfg['Servers'][$i]['AllowNoPassword'] = TRUE;
Save it.