Updating all ListView items together instead of one-by-one?

Question

I have a invoice entry form in ASP.Net 3.5. I have a FormView for the main invoice form and a ListView for the invoice line items. I don't want to commit each line item to the database individually when the user edits them. I want to commit them all as a group when the user clicks a button to update the FormView. I suppose I could bind to a datatable and manually retrieve the value from every control. However, I would prefer to use a LinqDataSource or ObjectDataSource if possible.

Is there an easy way to accomplish what I am trying to do there? I'm not married to the FormView/ListView approach, if there is an easier way.