I like the idea however, at a glance, it appears no one registered with an email address (well not "no one", but very, very very few) since it's not a required option.

I did make /f/cryptography a front page / featured forum after another member made it and thought about making a "key exchange" or PGP Practice type forum to allow users to practice their encryption skills (which I need to do as well, since it's been mostly just that... practice). You're free to create something like that if you wish, I'll probably make ti a featured forum too.

I know that's not really what you asked but in short: There is no plans to implement that just yet. If this site continues to gain traction I will likely set up a development mirror (with fake populated data, not real user data) for community development of things like that so we can form this community into exactly what we want. But for now, it's been 36 hours and I've received a lot of feature requests that I can't make happen... yet. :)