I did, it works, but since the 3G is asimmetric, I get a small bandwidth for upload, so I have to shrink the stream to minimum term. Now it works well only HDSPA or similar connections, good in towns, but outside it's good for ingoing connections like WEB navigation. Also rapid changes in network speed create buffer full situations. I was in telephony since 1990, I have written PABX's firmware, but VOIP swept my experience away. I have also many CTI applications, but only with POTS for extensions. Digital Trunks like E1 are my only digital experience.
If I have time I'll write (or port) a stream compressor... Hope that it won't kill the phone!