Some great ideas here Luigia! The slinky idea reminded me of a spring reverb I owned for a short while(the Ekdhal Moisturizer) which had exposed springs. I really enjoyed running sounds through, even something like a simple drum track, and then playing with the springs in different ways, even just breathing on it would yield cool effects.. Now I miss that weird machine..

On a side note, I just posted a thread about a system makeover I'm planning and I would greatly appreciate some of your thoughts(if you have the time)!

Sorry OP for the total hijacking..