How would I go about forcing a screen pop on a user's SF.com session?  For example, a caller dials into a telephony platform which asks for an account number.  Then the telephony platform utilzes a web service to identify whether or not the caller is an active lead.  Once confirmed and the call is delivered to an agent (using both SF.com and the telephony system), how can the user's SF.com session be directed to display the corresponding caller record?