One of the best features of the old E-Mu Ultra samplers was the convolution function in the sample editor. You could convolve any two arbitrary samples together to get some really crazy and unpredictable sounds. It would be great to have this in the Renoise sample editor. I suppose you could accomplish the same thing with a IR processor plugin and rendering track effects but having it directly available in the sample editor would make it really easy to use.
I still think this would be very powerful.
This is a very good suggestion indeed!
There already is a mix paste in the sample editor -> select, copy, switch to a new sample right click -> mix paste (multiply)
I will try that today, thanks! 
Is this convolution or amplitude modulation? It seems like the latter to me.
Yes, thats just AM, but also produces wired stuff.
This is definitely cool but convolution would open up a really wide range of sounds, anything from reverb irs to strange sound manglers like the ones at http://www.spiritcanyonaudio.com. Any linear dsp process can essentially be encapsulated as an audio file this way.
Thanks for taking the time to discuss this, by the way.