Creating phonecall

The main issue you will face in this case is assigning 'to' value to phonecall.

1. For 4.0

//first create the activityparty type object like

activityparty toActivity = new activityparty();

//Then assign partyid

toActivity.partyid = new Lookup("contact", contactID);

//Assign that activitypartyobject to 'to' of phone call.

phncall.to = new activityparty[] { toActivity };

service.Create(phncall);

2. For 2011

Guid contactID = new Guid("A11111F7-208C-E011-B5F4-000C29FABFAC");

PhoneCall phncall = new PhoneCall();

//first create the activityparty type object like

ActivityParty toActivity = new ActivityParty();

//Then assign partyid

toActivity.PartyId = new EntityReference("contact", contactID);

//Assign that activitypartyobject to 'to' of phone call.

phncall.To = new ActivityParty[] { toActivity };

service.Create(phncall);

It will work.

If any issue just let me know.

thanks