bapu
Good thing there is only one of me.

Says who?

smallstonefan
I saw (but lost the link to) a video where I guy was using Fractal's CabLab VST to run a cabinet simulator on a synth. I thought that was very interesting...

I have messed around with Amplitube and TH3 on synth sources, with some interesting results.
 
But I think one of my favorites is running a synth through a Leslie cabinet simulator! 
 
Break the rules, think outside the box!!!

Sure. why not. instant departure from the 'same ole same ole'.

I use a cabinet sim on a cleanly played and recorded harmonica when it wants to have more of the "Blues harp" type of sound. I'll usually throw in a touch of amp distortion and roll off the highs and slightly boost the lower mids.
The free Voxengo "Boogex" amp and speaker simulator vst is perfect for this:
http://www.voxengo.com/product/boogex/
 

timidi
Sure. why not. instant departure from the 'same ole same ole'.

This post is the winner! I just ordered the VST version of Cab-Lab to play with (I have the stand alone and a ton of IRs). :)

It can definitely yield some interesting results. You can also use IRs from different places like, the insides of boxes or synthetically made IRs. I believe spitfire audios new synth is based off of this.

bitflipper
I use them on EPs. But that's hardly radical, being not far from a guitar application. I can't imagine what benefit there'd be using one with a synth, unless that combination just by chance happened to accidentally result in some pleasant EQ. Which is really what a speaker sim mainly does - it's a complex filter.

Ditto.

A synth is just a complex filter as well.

Some free speaker cabinet impulses can be downloaded here:
 
http://www.grgr.de/IR/
 

cool thanks! I actually own a bunch of IRs I bought for my Fractal. I'm going to play around with some sound sources and various cabinets...