What are some novel ways to block spam?

36 hours after you join before you can ask a question.

Most suggestions that can be made would also deter legitimate new users from signing up, which is something we really, really don’t want to do given how small the userbase for Fluther has become over the last few years.

The auto-moderator recognizes a very common pattern of spam that we typically get (link included in the title of the question or at the very end of the question description) and kills the post if the poster is also new / low-lurve. Looking at my emails now, it looks like the auto-mod is killing at minimum about 4 spam posts per day.