I see Twan's directories intermixed above - generally those are good for blogs on his freehosts (thumblogger, sexusblog and sensualwriter), or in some cases blogs hosted on your own domain. In other words, there's little chance of getting a blog on another freehost listed on those directories. See
http://www.adultblogresource.com/submitter/ and the alternate submitter that I don't have the link for in front of me. New users to Twan's blog platforms have to get their blogs approved first, so if you want to eventually use them you should probably go ahead and sign up now.
Sexbiro is another good freehost, I might add.