I just submitted two blogs to Technorati. It appears that they want you to make a new post containing the claim token. I have been validating many sites for many purposes (e.g. analytics), but most of them required a special tag somewhere in the code or a DNS record. Never it required visible content.
So, supposed I followed the instructions and pasted the code (7RHXV5MMZ84Z, yeah, I’m getting verified) in a blank post. This will go to all existing readers subscribed by RSS and email and to all services that aggregate your blog. And they will see something completely irrelevant. If you have ten readers and you do it on a Saturday evening, that would probably go unnoticed. And you can edit an existing post, and add the token at the bottom, so that nobody notices. But the idea is far from great, and following the instructions will lead to confusion.
I’m aware that owning a blog doesn’t mean you can add headers or add dns records. But you can certainly add the code somewhere on your blog, be it the profile page. And there have to be more than one option for that. I would just go and add a widget with a hidden input containing the code, and it would work without disturbing any reader.
I guess this has been the case with Technorati for a long time, and I’m really surprised that it is still the only way to do it.