Is there a whammy plug in?

This is probably the wrong thread for that, you'd be better off going to the Production Tips area.

buuut. the easiest solution i see is using a pitch shifter. I use the pitch shift audiosuite in pro tools in a semi similar fashion. although it will be much less realistic as a whammy bar doesn't just pitch shift strings, it lowers the tension.
 
There's one in Guitar Rig 4 but it isn't that great sounding to me...nothing does this as well as the original Whammy pedal although some other pedals / hardware come close. Maybe there's a plugin but I haven't found one yet.
 
Boss Super Shifter pedal comes close, band I was recording lost his whammy pedal between sessions and brought one of the Boss units in for the dives and it turned out great.
 
Yah I just use the tuning peg for long dives. although the one you posted sounds more like a pitchshifter type thing than an actually bar anyway.
 
Yeah, it's written "Equipment (gear, DAW and plugins questions and comments)" on the top of the page. :)