Hi, I'm designing a IM client that use Jabber to communicate with a Jabber server. It also has a Jingle communication tool that enables the users to talk with each other ( PC2PC calls ). Now I want to add PC2Phone and Phone2PC capabilities to my system. As for PC2Phone I think it only requres a contract with a VOIP provider and some code writing to enable that, but as for Phone2PC, I think I need some special hardwares. This means that for example when you call a phone number that is assigned to a user, his/her IM client will ring, so that he/she can pick it up and answers online! If he's away, teh caller will leave a message. This is like how Yahoo Voice workd ( voice.yahoo.com ). If anyone has such experience please share here and help me in this regard. Thanks :)