This remarkably fun sound has been made famous by England's very own Reeps One. It's extremely useful in dubstep and drum and bass routines in particular, and once you get the hang of it it's quite easy to do.

To make the sound

1 - Learn the lip oscillation
2 - While doing a lip oscillation push your tongue forward to get a "wob" sound
3 - Lather, rinse, and repeat
4 - For the alternative sound, do the above to the side of your mouth without using air from your lungs. You can hum doing this

Peace, love, and throwing a wobbler

-FT