When .Mac overhauled their interface late last year, I was surprised and relieved by the vastly improved functionality. As someone who is self-employed, I like to work remotely, but am often frustrated by the lack of Mail.app support in public wi-fi spots (port blocking due to spammers, I am told).
Even with the .Mac improvements, I was still stuck with my POP3 webmail (Horde), which is perfunctory at best. I have been wishing .Mac's webmail would let me access my POP3 mail (I even considered emailing Apple about it). Well today, I stumbled across the setting, and found that it is very much possible! Click the Preferences link, then the Other tab, and the first section is External Account. You can enter one POP account to check in addition to your .Mac email.
My remote workflow has just improved!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20070105055526546