Hayley asked me to install a web mail client on her domain a while back which might get past her work’s web filter (they don’t like you checking email at work). I came across RoundCube Webmail and got it installed in 5 minutes.
Haven’t had time to really put it through it’s paces but the interface uses AJAX to good effect, much like GMail, but less cluttered. It certainly beats NeoMail, Squirrel Mail and Horde which were the pre-installed options bundled with cPanel and I would highly recommend anyone interested try it out, despite only reaching a 0.1 beta release it seems to handle basic functions faultlessly.