Tell me if you'd like me to add you to the list of folks who can use that tool, and you can add addresses to your black/whitelist from your web browser.
To get this working, I read these docs:
The INSTALL file from this dist:
The main bit is that you need to turn on the -q or -Q flag for your spamassassin daemon. For Debian-based systems, edit /etc/defaults/spamassassin
You'll also need to make a small modification to /etc/spamassassin/local.cf
There are instructions in the first README file for creating the spamassassin database in mysql, but if you need help, contact me and I'll walk you through it.
irc://irc.freenode.org/mysql and irc://irc.freenode.org/spamassassin are great resources as well.
Next step is to get whitelisting built in to Thunderbird. But I ask that someone else in the community do the leg work on this. :)