I want to suggest another way to look at the spam. First, I don't think removing links will help. I am webmaster for a site that gets 1500 visitors/day and I have a moderated guestbook. No spam links have ever been posted on the site -- but still every day spammers send me rubbish posts that I delete. This has escalated in the past couple of months, so I've put in filters, but some stuff gets through to me -- even though they get no "reward" for their actions.
Second, one of the interesting concepts we've talked about with Tom is that terrorists "win" when they get us to change our behavior in response to their efforts. Making links not clickable and preventing attachments (IMHO) will not stop them. But it hurts the good guys (that's us!).
There are a couple of other options. Because of all the activity, posts scroll by, and the spam makes it go even faster. I've archived a few conversations that I didn't have time to read immediately and have posted archives temporarily in response to requests to "Please save the weekend for me!" But that's not a good solution. Could we make the board longer (save more posts)?
The other option is of course a "real" bboard forum where people have memberships and all that. Archives would no longer be an issue. It would slow the spammers as they would have to join first to post. Frankly I like your streaming board better, though -- it is quick and easy to read and post.
regards always,
Donna