Particle systems, explosion?

Hi, Any advice on how to set up an "explosion" effect using SIO2emitter? I would normally subclass this, but... what's the best way to set up 'one shot' particle systems like an explosion? I noticed SIO2emitter supports IPO curves, perhaps I could use these?

Thanks,
--yarri

FWIW, I wound up changing the parabolic equation of the standard creation/render callbacks by tagging the emitter with sio2GetElapsedTime() and forcing the particle lifetime to zero. Haven't found a good way to cull the expired emitters, but performance on the device seems ok.
--yarri