[Asterisk-Users] PDA's over SIP channels on Asterisk

[flickds]

Is it possible for two PDA's to communicate like telephones via SIP channels 
on a PC running Asterisk?  If that is possible, does there exist any 
applications that can be installed on a Zaurus 5600, which is a PDA with an 
Xscale processor running on a Linux OS, that can essentially turn it into a 
softphone?  Thanks in advance for any input,

Daniel