Hello Mike,
I have already worked with mini2440.and did cross compilation of linphone for s3c2440 ARM-Linux board successfully.
You have to follow the instructions given in
the README.arm within linphone's source.
Experimented with command line interface (Linphonec) that was worked fine with mini2440 board.
GUI development was not completed. look the below forum message that was posted under me.
http://lists.gnu.org/archive/html/linphone-users/2011-01/msg00040.html.
It would be great that sombody can develop GUI as well for that board.
regards,
Nirav