This page from Diana Deutsch has some excellent examples of auditory illusions – This speech to song example is really suprising – you should take the time to listen to the mp3s provided…
http://www.acoustics.org/press/156th/deutsch.html
This page has some great interactive examples of optical and sonic illusions
http://www.cs.ubc.ca/nest/imager/contributions/flinn/Illusions/Illusions.html
and finally this one, its a bit silly but works really well,the ‘virtual Barbour’ shop or ‘hair cut’ you need to use headphones to listen to this one…
http://fn4.putfile.com/getfile/1202092920video1234sslash2523182989.mp3
