Dr. Kenneth S. Olson is a linguist at SIL International, a Christian organization based in Dallas that studies lesser-known languages. Last spring he proposed that a sound common in 70 African languages, a labiodental flap, be afforded its own phonetic symbol. Now, it has been.
The sound is made by the lower lip moving back and forward–and produces a vibrating buzz that’s sometimes capped by a faint pop. The symbol looks like, well, here’s Geoff Pullum’s description, a peer of Olson’s:
[It is] as if a fishook R had been slammed leftward into a lowercase v so hard its vertical had merged with the right leg of the v, and the dangly bit had been left hanging there like the drain pipe out of an upstairs toilet in a partially demolished building.
Either that or a lowercase v with a hook on the right end. Take your pick.