Some blogging news.
I made an upgrade to Diggers Realm a few months ago and Movabletype installed a nofollow plugin by default. I've been meaning to get around to turning it off and now have. I believe that those that contribute to Diggers Realm deserve to not be hindered and should get credit for anything they post or trackback from.
If I can keep spam under control then it will remain off. I urge other bloggers to do the same if they can manage their spam reasonably.
For comment spam, adding a captcha -- those little images of letters and numbers you must type in when posting -- and a mandatory preview is a great way to cut down on spam. I have seen it drop to near 0 since I've implemented it.
Trackback spam is a different story altogether. A good spam filter catches the majority of any that comes in, but it also tends to catch some legitimate trackbacks as well. If you sent a trackback and it doesn't appear, please contact me and let me now.