I know this is really petty but does anyone know if there's a way of identifying the file that makes the standard key tones and substituting it for something more interesting?
Key tones
No, because whatever file (data or application) it is, it is in ROM (Read-Only Memory) and is not changeable or overridable [is that a real word?] on this (or any other Series 60 phone) without changing the firmware (which means only the phone manufacturer can do it).
OK - cheers.