Like when you commit a poem/lyrics to mind, and just convert it to a string of digits on the fly... using the phonetic/mnemonic number system, so the spectator can test you because you earlier wrote down the (rather meaningless) string of digits. Several good lines of pseudo-math babble, justifying the presentation of these numbers, spring to mind
(maybe the venerable Rand Corporation book -
http://en.wikipedia.org/wiki/A_Million_R......Deviates - and, ahem, perhaps a couple of gaffs!) Anyone perform this, and, if so, how does it go down?