Comment and trackback monitoring

With some reluctance I've had to turn on trackback and comment monitoring for this blog. I've been getting increasing amounts of spam, mostly trackbacks, and it's becoming annoying. I suppose it could be my fault for posting once, a long time ago, something about online poker.
If you post a comment or trackback, there will be a delay before it appears, as it is sent to me for approval. One way to circumvent this is to sign up for the TypeKey service, but I haven't made this mandatory.