[jimnutt]

So, I'm sure this idea has holes all over it, but how about a very simple service that you log into with your PGP public key, then would allow you to post encrypted messages to other PGP public keys and retrieve messages posted to your public key. It could be fully anonymous, depending on your choice of keys. It would be very similar to the mixmaster remailers, except it wouldn't actual mail anything as it wouldn't have any identifiable information other than the public key.

[dredmorbius]

PGP itself leaks a huge amount of metadata. A known problem on open mailing lists and Usenet.