Perhaps the most expedient way to do that is with a personal web page?
After all, it is not the physical appearance of the brain that one is
interested in, and if it were, that's easy to fake. One's body of
written work (or artwork, or invention) is hard to fake--in fact it's
possible to verify with crypto-signatures, and gives direct insight
into the mental processes that created them. It could easily become
a standard of social activity to exchange URLs instead of phone numbers.
If you'll excuse me, I'd better go update my site now...