My brother lives in (on?) Hawaii, and after reading Dan Sherman's story we have been discussing our own tests of intuitive communication. It seems like there is some type of 'knowing' we have as siblings - that has always been there, and maybe supressed by cultural conditioning over the years.
Our idea was to send an email with the letters 'IC' in the subject, of the communication sent. It could be an image, or a taste, or a memory, etc. But similar in the conditioning/training one can read about on remote viewing, we thought maybe that email and its details could wait until the receiver wants/needs to verify the message. Another idea we had is that the instantaneous nature of time may not be a requirement - for instance could I receive what he sent hours or days later?
There is an interesting book on animal communication I read this year which may be helpful, called
Learning Their Language by Marta Williams (
http://www.martawilliams.com/)