Functional Programming is, IMHO, the wave of the future.
Problem is, it's been the wave of the future since some
while in the past.
Start at the
Haskell page,
and/or the
OCaml page,
and/or the
Lambda, the Ultimate Weblog .
Oh, and if you use USENET,
comp.lang.functional.
Later, look for Erlang, Mercury, Oz ...
and maybe O'Haskell, Scala, ...