Dear old Blogger is having a hissy fit. I don't think it's me, as others seem to be experiencing similar ennuis.
If you have been trying to post a message, you've probably been confronted with a boring old error message telling you politely that your request cannot be processed. My apologies on behalf of Blogger, and if it's any consolation, I can't post messages on my own blog either. Just posts.
Just hold onto your hats and normal service will be resumed shortly.
Edited to say that normal service has now been resumed!