Okay
Umm.. obviously I don't know if you've already sorted this, and I don't know if you've had any of these folks on before, and I don't know any of
them personally or anything, but I'm just gonna throw a load of suggestions in and I guess you can have a look and maybe some of them may be good for
future shows, or maybe they'll just help you think of someone else..
Scott Stevens of
Weather Wars has some interesting and unorthodox ideas about what's going on with
the weather
There's this super website about
near-death experiences - there may be someone there you could
interview.
Bryan Hance has been trying to solve this
really weird mystery for the past umpteen years,
since finding a strange announcement in his university newspaper.
Maybe someone from the
Edgar Cayce organisation ? The British centre is run by a guy named
John Walsh up in Durham. You could ask them if
they're still hoping to find the lost records of Atlantis
There's this guy,
Sean Tudor who's written some really interesting stuff on phantom hitchhikers and haunted
roads.
Rene Zandbergen, who's been working on the mysterious
Voynich Manuscript
Maybe someone from the
Scottish Society for Psychical Research for some stories from North of the Border?
Stuart Wilde, the 'urban mystic' seems to be an interesting character.
Or.. howsabout Semir Osmanagic - the chap who's digging up the
Bosnian Pyramid 
Yay, that could be
interesting.
Sorry, have to leave off now, need to sort out some food.