I agree, with firewalls everywhere, specially at work, would be nice if cf was available on a standard port.

But, until then, here are some things you can do.

1. Buy a shell account, or web service with a shell account, that permits mudding. I don't have any good ones, but they are out there.

or

2. Get SSH or telnet hosted on your home PC, with a direct connection to Internet. Even dialup will work OK for CF. Don't need to install linux, try Cygwin. Here's a great tutorial: http://pigtail.net/LRP/printsrv/cygwin-sshd.html
Then, you ssh into your home PC, and telnet to CF from there. Can install tintin++ or tinyfugue as well, though both are a royal bitch compared to zmud or jmc, until you figure them out.