To get contact with other fans:

There is now the One-Word Mailing List, devoted to the discussion of John McLaughlin and beyond. There is also mailing-list archive.

There is also a Miles Davis LISTSERV, where they discuss varies of topics, including sidemen of Miles (i.e. also John McLaughlin).

And, of course, there is a newsgroup called rec.music.bluenote.

The John McLaughlin Internet Fan Club.