Is it possible to use yahoo free voice chat in any of the pda mobile or communicator mobile phones?

im connecting my pc to internet via nokia 6670 which has GPRS enabled gsm connection.so i used to connect net in mobile also and pc via mobile also.now i want PDA type mobile or communicator mobile by which i can connect to internet and use yahoo voice chat and browsing in itself ...simply it should work as small handheld laptop...which mobile will be more useful efficient for this feature?please answer me...