Your Topic Reminder to Big Al on the thread about Scalia got me wondering if there would be a way to link posts and responses across threads. For example, if someone wanted to respond to Big Al, their response would appear in a different thread, but still contain a reply notification linking it back to the original comment.
A generic "Reply in a Different Thread" button is probably just asking for a mess, but perhaps there's some programmer wizardry you could come up with that would let moderators "tag" an off-topic post such that all responses are automatically shunted to a designated thread where it is on-topic, and a reply notification is left behind?
I have no programming experience, so maybe this isn't as simple or as useful as it seems to me; but I thought I'd throw it out there anyway.
The programming is probably straightforward, the design probably much more difficult. Perhaps instead of having some extra button or link with each message, maybe something could be added to the reply page.
I'll add this to my list of "ideas to think about." It's in the same realm of ideas as those related to improving administrators' ability to spawn new threads from a portion of an old one.