I think someone will find this quite useful.
Thanks for sharing!
I have posted the code (without the sound file) and a link to the first post in this thread on the wiki at http://wiki.droidscript.me.uk/doku.php?id=sample_code:pincode
so that people can download the SPK from here.
Unfortunately, we cannot upload spks to the wiki.
Regards,
Sankarshan