The use of the program depensd on what phone you have..
With some phones you can use your carputer as an handsfree, using the cars speakers and an mic.. You can send and revieve sms, access your phonelist.. It mutes the music when you recieve calls.. This is just some of the features..
Otherphones can only revieve sms, not send..
Some only access phonebook..
A list over compatible phones and witch feature your phone have can be found on www.phoco.net
Here you can also find the complete list of features..
You can use bluetooth, cable or irda.. But this depends on the phone.. Go to the website, and you can read all about it there..