Sort one list by another

One way of doing it:

List<int>  order = ....;
List<Item> items = ....;

Dictionary<int,Item> d = items.ToDictionary(x => x.ID);

List<Item> ordered = order.Select(i => d[i]).ToList();

Another LINQ-approach:

 var orderedByIDList = from i in ids 
                       join o in objectsWithIDs
                       on i equals o.ID
                       select o;