Starts at 4:33 here:

http://www.youtube.com/watch?v=PEe2uJEIrkg

Its sounds like a rubber-band stretched and brought back to its normal length. To me that sounds like pitch bending, but its so fluid (I couldn't draw it or play it in)... Suggestions?

Thanks!

Maybe LFO controlled by mod wheel?

The initials one's are pitch bends. Maybe I'm hearing something different due to the other effects in there. Will play with it more.

I was having great fun attempting this before my battery died

Anyway, I got very close with an LFO attached to the mod wheel (as previously suggested).
The trick was approximating a rubber band as the OP mentioned.
If you release a rubber band, it wobbles initially very quickly before slowing down (ie the curve is exponential).

With that said, assign mod wheel to LFO speed (-ve), set LFO to 1/64, draw an exponential curve in the mod wheel automation lane and sequence. Viola!

Trying the LFO-Mod Wheel, but the whole sound is effected (since the LFO has to have a minimum value).

it's probably a guitar (got neat overtones to chug at) with some automated LFO (how you control the cc/midi is quite extraordinarily irrelevant) assigned to pitch/playback speed.

you can get less obvious rubber effects preserving tonality using FM synthesis

Can you explain this more? I've just started looking into FM and I don't see how pitch bending will preserve the tonality?

It's almost certainly an effect added afterwards, and in all likelihood from the eventide processor they use, but you could possibly use a combination of a pitch shifter and LFO type tremolo plug in to get the 'type' of same effect...

they also use smartelectronix plug ins, but I don't think for this sound.

@ OP: Do you mean the bubbly sound that continues several times or the percussive one-off that starts around 4:33?

oh I mean fiddling around with FM parameters instead of pitch. no pitch bend involved! you can have a melody with stable tonality while altering the timbre with FM index, cutoff, resonance, distortion etc. fun stuff! nothing to explain really, just a hint.

The one that sounds like a guitar. Like the whammy bar is depresses on a sustaining note and it bounces back up.