I've added a new subscribe to newsletter feature to the Philosophers' Carnival homepage. If you fill out your email address, you will be added to the mailing list.
What this means is that you will receive automatic email notification:
1) A few days before an upcoming carnival, as a reminder in case you wish to submit a post to it.
2) Immediately upon the publication of each new carnival.
You can unsubscribe at any time.
Many thanks to Jeremy Pierce for the idea of setting up a mailing list. If enough people sign up to it, this should solve the publicity problem quite nicely.