It seems like every time I look away for too long we get another influx of bots. The most recent round came in and started posting links to who knows what.
To combat this, we are back to moderator approval of new accounts. I have also added a dozen security questions. New members will have to answer three randomly chosen ones at registration.
There is also a new favourite character(s) profile field that is not only required at registration, but longtime members will be prompted to fill this out if they wish to make changes to their profile. I hope you don't mind this too much. It just seemed like a good measure to help weed out bots that make it past the security questions.
I hope the other options above would let me lift mod approval in the future, so there isn't so much of a barrier to pass before new members are able to post, but we'll see.