Over the last few weeks I've been getting a lot of spam on the blog - dozens of posts per day. I tried moderating comments and although that stopped the comments appearing on the blog, it cluttered up my email system to such an extent I was worried I'd miss important messages.
Because of this, I've disabled anonymous comments at least temporarily. Sorry about that. If there's anyone who would like to comment or ask a question and isn't able to set up an account to allow them to do so, they're welcome to email me (address on 'contact me' page) and I'll post it for them.