A Dispatcher reportered attempting communications with a B757 international flight which diverted without prior communcications; into a US airport with no customs service.

Narrative

An international flight decided to divert. Flight was enroute when I noticed in my flight monitor screen that the flight had listed its destination as a Diversion Destination. I sent the Captain an ACARS message concerning to no customs available at that airport. I called Operations with the Customs information to call. During this time I received calls and a visit from Chief Pilot concerning the flight diverting. During this time I tried to get in contact with the flight; I was worried of a possible emergency. I noticed the flight was at approximately 9000 FT. With all the concern of not knowing what was going on with the flight and all the phone calls I made and answered; I did not have time to send either via ACARS or radio all destination information needed. At one time I even called via destination frequency to get ahold of the flight but with no success. I was able to talk to Operations to confirm radio operation but not the flight. I think the Crew should have made a better effort in informing Dispatch of what was going on.