A small collection of sounds (one of which is noise) wouldn't be a bad idea. It's more likely something interesting would come out sources with a bit of contrast....maybe four sounds? Two minutes.
If there's anything that we (as in those of use who joined in with the 1st OT lab) will attest to, the OT is pretty much capable of making any kind of sound with even the most limited set of samples. For the doubters, take a browse through the tracks that got submitted last time - tons and tons of sonic variation from a frankly ridiculous set of sounds. So much fun!
A real challenge would be one sample. And that one sample should be white noise, IMHO.
I'm with Neil, 1 sample, white noise - I think it will be a good excercise to push creativity, its not a competition so just go crazy and see what you can do, and where it takes you.
I'm happy to provide a sample and upload it to the files area, whatsay a 2 second blast of white noise?