It has been several years since any significant changes in anonymous remailer technology were proposed. Much of the latter day thinking has been directed more to Democracy Walls such as MN, freehaven, freenet as possible improvement on good ole Usenet alt.anonymous.messages. While it is still a bit premature, there are some intriguing possibilities in the evolution of Sun's new offspring, JXTA. In particular, the peergroup concept which allows for the dynamic formation of a routing graph amongst anonymous but authenticated nodes. There is a core JXTA security project which is supposedly finishing off an implementation of the basic crypto components including some version of key exchange and encrypted messaging (also toying with some reputation extensions which _might_ be useful). The basic JXTA node protocols use random id's, not IP addresses, domain names, or other universal namespaces.. Off the top of my head it might easily be possible for a remailers to participate in a JXTA peergroup, mixing messages with peer-2-peer xfers before a message was emitted through SMTP at the exit point. Intermediate nodes would not need to even have ICANN/IANA registered public SMTP addresses, simply persistent peergroup nyms and public keys. The JXTA protocols allow for non-tcp/ip transports as well, so an intermediate point might communicate using bluetooth, or infrared. Furthermore, by executing the transfers using a more general purpose protocol than email it would be possible to extend the remailer model to other communications channels and exit via IM, IRC, Usenet or cellular SMS. With a peergroup infrastructure it would even be possible to devise some group advertisement protocol where a remailer node or eavesdropper _never_ knew to which specific address a message was forwarded, only to what group of addresses. As I said, JXTA is a pretty raw beast right at the moment, but some of the groundwork is being set out which might make cooperative anonymous communication possible with an even lower public profile than SMTP and with a mixed mode of transport which could further frustrate analysis. There is even an incipient (although deeply flawed from a 'punk perspective) proposal to add a micropayment service into the mix. <http://www.jxta.org> A peergroup based mail services does raise some interesting trust metric challenges, though. And -- until there is a broad population of JXTA users and traffic -- the cover is mighty thin compared with smtp.