I just posted a long review as a guest entry. This entry was posted into the comments of another, unrelated entry. Since it did not have a relationship to the content of that previous entry, it's technically spam. Therefore I did not publish it as a comment.
I noted that I would prefer folks to refrain from doing this. Sometime soon I suppose I will have a set of contributors' and commenters' guidelines to post someplace which may help to forestall confusion.
However, I'd love to see more unsolicited reviews coming in to be published here!
At the moment, we don't have a good method for publishing them, so send them directly to me at email@example.com and I will run them as guest entries as I did previously. Additionally, I am initiating a dialog about continuing to expand the contributor base here. With luck, I will come up with an easy way for interested people to begin posting here. Stay tuned!