C# WCF ListBox Data control, Multi-user, how?

I managed to get my data via WCF to my client app, now, if I have a huge list of for example persons, and each person has a coulpe of fields like "Name" "Address" etc, using a ListBox to list them, do I have to download the whole list into my ListBox? Is it possible to have some data aware control which doesn't download it "all"? Sort'a like DataGrid? What is the best way to do this? IMPORTANT POINT : There are more than one client using this at the same time as well. What if client 1 changes the DB, how does client 2 get aware of this change?