Anti-spam measures

I’m looking at a couple of anti-spam measures for the blog, and welcome feedback from people as to which would be the least hassle for them.

Option One is to reintroduce the “Are you Human” test where a graphic is displayed showing numbers and/or letters which you have to type in. At present the automated spam attacks can’t scan the graphics and hence very very little spam gets through. How-ever sometimes the tests can be hard for even humans to get on the first go.

Option Two is some sort of whitelisting which trusted commenters have their comments appear immediately, while others face a delay until individually approved. The typekey system is meant to do this but I am havign problems getting it to authenicate. Regardless there are plugins which allow me to whitelist purely on e-mail address for example. This means some commenters will have no hassle at all, while others will have delays. Also requires some time spent moderating.

At present the blog attract a spam comment every two or three minutes which comes close to 1,000 a day. Now the anti-spam filters catch 90% to 95% but even 50 a day getting through is far too much, and is taking up too much of my time manually junking it.