vocalizer such as izotope vocalsynth,
delicate editing tool such as celemony melodyne,
pitch altering tool such as dmg audio pitchfunk
- those all and many other are fun to mess with ;)

Thank you for all of the suggestions.  I've been going down a few of these rabbit holes and finding some outrageous sounds.
 
Craig - I can't find that plugin from your screenshot (voxtools).  I've had every version of Sonar Producer for a long time and just installed the new Platinum producer this week.  Where do I find it?  Great song reference btw.
 
I just got iZotope Trash2 in the mail from a Stupid Deal Of The Day (installed it yesterday), and am finding some pretty wild options in there.
 
 

sethmopod
 I can't find that plugin...(voxtools).

In the Plugins tab of the browser look in FX Chain > Anderton Collection > VoxTools

Found it.  THanks!

I could sing it for you.  That would be pretty messed up.
 
www.themightykonrad.com

sharke
Don't be afraid to put a vocal through an amp sim to really grunge it up. I use Guitar Rig for this, not only because of the amps but also because there are some very cool effects chains in it too. A sound I like is to put a vocal through an amp sim with a crunchy sound, then use a harmonizer (there's one in GR) to add a harmony a fifth higher (7 semitones). And then put it through a flanger lol. 

Guitar Rig (5) also has those wacky step sequencing/parameter trigger tools that let's you map to any effect/sim/parameter and program in some wild changes and/or changes based on the audio input being run into them (ADSR Tool).
 
Of course Sonar hasn't come with Guitar Rig for a while now and that was a limited version (GR4 I think). I don't think those triggering tools came with it. One of the very few things I dropped money on to upgrade and (even though I fell out of love with it for a brief while after TH2 came out) it's definitely been worth it.

Having a couple of problems:
z3ta+ - I can't get any sound to come out of it.  When I put it on the bus, no sound.  Turn it off (via the power button in the fx rack) and sound comes back.
 
VoxTools - The Mayhem Distortion button does the same thing.  When I hit the button, it cuts off the audio.
 
Thoughts?

Make sure to use the z3ta+ FX plug-in see http://forum.cakewalk.com/FindPost/3369383

PS: If you are going to do a bunch of layering to smash a bunch of effects this is an EXCELLENT use for the new Aux Tracks. Basically set up a bunch of Aux Tracks and feed the original vocal track into all of them. Then add your effects on the different Aux tracks.
 
That way you aren't loading up the project with extra clips by cloning the original (which can slow down the system/be hard to keep track of) or busses (better to keep all your vocal mayhem in a nice neat folder in the Track Pane).
 
It also gives you a bunch of extra options as far as automation AND you can use the PC QuadCurve EQ on every Aux Track (you can only have one QC instance per track).
 
aaaaaand they can be recorded into (unlike busses) which means you can do realtime effects, record them into the Aux tracks then mangle the resulting clips further/individually with DSP and/or Region FX or whatever.
 
Then it can all terminate into a single bus (or multiples if you want) for final sound sculpting.
 
Also you can mute the main output of the original dry track (while the sends to the aux tracks are still active) to completely take it out of the equation OR automate the output for a wet/dry effect (but you have to make sure the sends to the Aux Tracks are PreFader).
 
 
Just some extra ideas for extra mangly goodness.
 
Cheers.
 

Got z3ta+ working now.  Thanks for the link.