Somatix has released Formant Filter, a free formant filter effect in Ableton Live rack format.
Just built this formant filter rack for Live. It is set up so you can sweep the frequency, fade between vowels, and scale the gain amount. When the formant is set to 0 the signal is dry.
Formant Filter is available for free download via Dogs On Acid.
Links
Download Formant Filter: click here