eok did manage to make the Nintendo DS-based SIP app from Samuel running on the iPod Touch!!
VoIP confirmed!!! « iPod Touch Mods
After Nintendo DS, here is another pjsip port along the lines of VoIP on Consumer Devices product line: internet telephony on the iPod Touch. It needs a hardware modification to make activate the microphone though, so definitely not for the faint of heart!
pjsip blog 