The Kuwako is a great and cheap piece of kit. Even if you have an e-pipe.
http://www.ivapour-elixir.co.uk/kuwako-1.html
http://liberro.co.uk/electronic-pipes
http://jazzepipe.com/index.php?route=product/product&path=38&product_id=61
http://www.epipemods.com/single-battery-pipes.html#
http://www.labuenapipa.com/en/e-pipas/