Artoo beep sequences for RCX

Before I try (and probably fail) to re-invent the wheel - has anyone made any
RCX/Spybot sound/beep sequences styled on R2-D2's beeping and warbling?

I'm looking to add some sound to a NQC-based robot, and I think it would be nice
to get away from my usual functional machine-like beeps, towards something
happier and friendlier. Artoo's beeping seems like a good approach, and before I
spend a lot of time trying to mimick it, since I'm pretty weak at sound, I was
wondering if it's been attempted already. Judging from a review of the
Mindstorms Droid Developer set, that's not the place to look for artoo-inspired
beeps, and Google isn't turning up much :(

Any leads?
Thanks
 - Justin